天天看點
傳回

oracle 遊标使用全解【轉】

-- 聲明遊标；CURSOR cursor_name IS select_statement

–For 循環遊标

–（1）定義遊标

–（2）定義遊标變量

–（3）使用for循環來使用這個遊标

--類型定義
       cursor c_job
       is
       select empno,ename,job,sal
       from emp
       where job='MANAGER';
       --定義一個遊标變量v_cinfo c_emp%ROWTYPE ，該類型為遊标c_emp中的一行資料類型
       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遊标

–使用的時候必須要明确的打開和關閉

--類型定義
       cursor c_job
       is
       select empno,ename,job,sal
       from emp
       where job='MANAGER';
       --定義一個遊标變量
       c_row c_job%rowtype;
begin
       open c_job;
         loop
           --提取一行資料到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;
       --關閉遊标
      close c_job;
```end;

--1：任意執行一個update操作，用隐式遊标sql的屬`性%found,%notfound,%rowcount,%isopen觀察update語句的執行情況。
     ```  begin
         update emp set ENAME='ALEARK' WHERE EMPNO=;
         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('遊标指向了有效行');--判斷遊标是否指向有效行
            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=;
                 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,使用遊标和loop循環來顯示所有部門的名稱
--遊标聲明




<div class="se-preview-section-delimiter"></div>

```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,使用遊标和while循環來顯示所有部門的的地理位置（用%found屬性）

declare

–遊标聲明

cursor csr_TestWhile

is

–select語句

select LOC

from Depth;

–指定行指針

row_loc csr_TestWhile%rowtype;

begin

–打開遊标

open csr_TestWhile;

–給第一行喂資料

fetch csr_TestWhile into row_loc;

–測試是否有資料，并執行循環

while csr_TestWhile%found loop

dbms_output.put_line(‘部門地點：’||row_loc.LOC);

–給下一行喂資料

fetch csr_TestWhile into row_loc;

end loop;

close csr_TestWhile;

end;

select * from emp

–4,接收使用者輸入的部門編号，用for循環和遊标，列印出此部門的所有雇員的所有資訊(使用循環遊标)

–CURSOR cursor_name[(parameter[,parameter],…)] IS select_statement;

–定義參數的文法如下: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(‘員工号：’||r_emp.EMPNO||’員工名：’||r_emp.ENAME||’工資：’||r_emp.SAL);

end loop;

end;

select * from emp

–5：向遊标傳遞一個工種，顯示此工種的所有雇員的所有資訊(使用參數遊标)

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(‘員工号’||r_job.EMPNO||’ ‘||’員工姓名’||r_job.ENAME);

end loop;

end;

SELECT * FROM EMP

–6：用更新遊标來為雇員加傭金：(用if實作,建立一個與emp表一摸一樣的emp1表，對emp1表進行修改操作),并将更新前後的資料輸出出來

–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程式塊，對名字以‘A’或‘S’開始的所有雇員按他們的基本薪水(sal)的10%給他們加薪(對emp1表進行修改操作)

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程式塊，對所有的salesman增加傭金(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程式塊，以提升2個資格最老的職員為MANAGER（工作時間越長，資格越老）

–（提示：可以定義一個變量作為計數器控制遊标隻提取兩條資料；也可以在聲明遊标的時候把雇員中資格最老的兩個人查出來放到遊标中。）

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||’ 工作時間：’||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程式塊，對所有雇員按他們的基本薪水(sal)的20%為他們加薪，

–如果增加的薪水大于300就取消加薪(對emp1表進行修改操作，并将更新前後的資料輸出出來)

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.’||’薪水變為：’||salInfo);

end if;

update emp1 set SAL=salInfo where current of crs_UpadateSal;

end loop;

end;

–11:将每位員工工作了多少年零多少月零多少天輸出出來

–近似

–CEIL(n)函數：取大于等于數值n的最小整數

–FLOOR(n)函數：取小于等于數值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||’已經工作了’||r_WorkDay.SPANDYEARS||’年,零’||r_WorkDay.months||’月,零’||r_WorkDay.days||’天’);

end loop;

end;

–12:輸入部門編号，按照下列加薪比例執行(用CASE實作，建立一個emp1表，修改emp1表的資料),并将更新前後的資料輸出出來

– deptno raise(%)

– 10 5%

– 20 10%

– 30 15%

– 40 20%

– 加薪比例以現有的sal為标準

–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，如果該員工薪水高于其所在部門的平均薪水，則将其薪水減50元，輸出更新前後的薪水，員工姓名，所在部門編号。

–AVG([distinct|all] expr) over (analytic_clause)

—作用：

–按照analytic_clause中的規則求分組平均值。

–分析函數文法:

–FUNCTION_NAME(,…)

–OVER

–()

–PARTITION子句

–按照表達式分區(就是分組),如果省略了分區子句,則全部的結果集被看作是一個單一的組

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;

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,使用遊标和while循環來顯示所有部門的的地理位置（用%found屬性）

--遊标聲明
       cursor csr_TestWhile
       is
       --select語句
       select  LOC
       from Depth;
       --指定行指針
       row_loc csr_TestWhile%rowtype;
begin
  --打開遊标
       open csr_TestWhile;
       --給第一行喂資料
       fetch csr_TestWhile into row_loc;
       --測試是否有資料，并執行循環
         while csr_TestWhile%found loop
           dbms_output.put_line('部門地點：'||row_loc.LOC);
           --給下一行喂資料
           fetch csr_TestWhile into row_loc;
         end loop;
       close csr_TestWhile;
end; 
select * from emp

–4,接收使用者輸入的部門編号，用for循環和遊标，列印出此部門的所有雇員的所有資訊(使用循環遊标)

–CURSOR cursor_name[(parameter[,parameter],…)] IS select_statement;

–定義參數的文法如下: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('員工号：'||r_emp.EMPNO||'員工名：'||r_emp.ENAME||'工資：'||r_emp.SAL); end loop; end; select * from emp

–5：向遊标傳遞一個工種，顯示此工種的所有雇員的所有資訊(使用參數遊标)

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('員工号'||r_job.EMPNO||' '||'員工姓名'||r_job.ENAME); end loop; end; SELECT * FROM EMP

–6：用更新遊标來為雇員加傭金：(用if實作,建立一個與emp表一摸一樣的emp1表，對emp1表進行修改操作),并将更新前後的資料輸出出來

–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程式塊，對名字以‘A’或‘S’開始的所有雇員按他們的基本薪水(sal)的10%給他們加薪(對emp1表進行修改操作)

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程式塊，對所有的salesman增加傭金(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程式塊，以提升2個資格最老的職員為MANAGER（工作時間越長，資格越老）

–（提示：可以定義一個變量作為計數器控制遊标隻提取兩條資料；也可以在聲明遊标的時候把雇員中資格最老的兩個人查出來放到遊标中。）

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||' 工作時間：'||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程式塊，對所有雇員按他們的基本薪水(sal)的20%為他們加薪，

–如果增加的薪水大于300就取消加薪(對emp1表進行修改操作，并将更新前後的資料輸出出來)

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.'||'薪水變為：'||salInfo); end if; update emp1 set SAL=salInfo where current of crs_UpadateSal; end loop; end;

–11:将每位員工工作了多少年零多少月零多少天輸出出來

–近似

–CEIL(n)函數：取大于等于數值n的最小整數

–FLOOR(n)函數：取小于等于數值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||'已經工作了'||r_WorkDay.SPANDYEARS||'年,零'||r_WorkDay.months||'月,零'||r_WorkDay.days||'天'); end loop; end;

–12:輸入部門編号，按照下列加薪比例執行(用CASE實作，建立一個emp1表，修改emp1表的資料),并将更新前後的資料輸出出來

– deptno raise(%)

– 10 5%

– 20 10%

– 30 15%

– 40 20%

– 加薪比例以現有的sal為标準

–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，如果該員工薪水高于其所在部門的平均薪水，則将其薪水減50元，輸出更新前後的薪水，員工姓名，所在部門編号。

–AVG([distinct|all] expr) over (analytic_clause)

—作用：

–按照analytic_clause中的規則求分組平均值。

–分析函數文法:

–FUNCTION_NAME(,…)

–OVER

–()

–PARTITION子句

–按照表達式分區(就是分組),如果省略了分區子句,則全部的結果集被看作是一個單一的組

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;

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

聲明 遊标 cursor
上一篇: 2015ACM多校對抗賽第四場 hdu 5336 傳送門：http://acm.hdu.edu.cn/showproblem.php?pid=5336 XYZ and Drops
下一篇: Hive-1.2.2安裝的過程說明

繼續閱讀