oralce plsql案例练习

以下plsql程序用的scott用户的dept,emp表。

案例1

--查询80,81,82,87年员工入职人数
set serveroutput on
declare

  cursor cemp is select to_char(hiredate,'yyyy') from emp; 
  count80 number :=0;
  count81 number :=0;
  count82 number  :=0;
  count87 number  :=0;
  phiredate varchar2(4) := '';
  
begin
  open cemp;
  
  loop
    fetch cemp into phiredate ;
    exit when cemp%notfound;
    
    if phiredate = '1980' then  count80 := count80 +1;
    elsif phiredate = '1981' then  count81 := count81 +1;
    elsif phiredate = '1982' then  count82 := count82 +1;
    elsif phiredate = '1987' then  count87 := count87 +1;
    end if;
    
  end loop;
  close cemp;
  
  dbms_output.put_line('total:'||(count80+count81+count82+count87));
  dbms_output.put_line('1980:'||(count80 ));
  dbms_output.put_line('1981:'||(count81));
  dbms_output.put_line('1982:'||(count82));
  dbms_output.put_line('1987:'||(count87));
  
end;
/

案例2

--员工涨工资。从最低工资涨起每人涨10%，但是所有员工的工资总额不能超过5万元，请计算涨工资的人数和涨工资后的所有员工的工资总额


set serveroutput on

declare

--定义光标:查询所有员工的员工号和工资
  cursor cemp is select empno,sal from emp order by sal;
  pempno emp.empno%type;
  psal emp.sal%type;
  
  countEmp number := 0;
  salTotal emp.sal%type;
  
  begin
  --查询所有员工涨前的工资总额
    select sum(sal)  into salTotal from emp;
  
  open cemp;
  loop
  --涨前工资综合大于5000则退出循环
    exit when salTotal > 50000 ;
    
    fetch cemp into pempno,psal;
    
    --若未从光标中取到值退出循环
    exit when cemp%notfound;
    
    --若当前的工资总额加上 当前员工涨后的工资大于5万则退出循环
    exit when salTotal +psal*0.1 >50000;
    
    update emp set sal = sal*1.1 where empno = pempno;
  
    countEmp := countEmp +1;
    salTotal :=salTotal +psal*0.1;
  
  end loop;
  close cemp;
  commit;
  
  dbms_output.put_line('涨工资的人数是:'||countEmp);
  dbms_output.put_line('涨后的工资总额是:'||salTotal);
  
  
  end;
  /

案例3:

--实现按部门分段(6000以上、(6000，3000)、3000元以下)统计各个工资段的职工人数、以及各部门的工资总额

set serveroutput on

declare 

    cursor cdept is select deptno from dept;
    pdeptno dept.deptno%type;
  
    cursor cemp(dno number )  is select deptno,sal from emp where deptno = dno;
    pdno emp.deptno%type;
    psal emp.sal%type; 
  
    count1 number := 0;
    count2 number := 0;
    count3 number := 0;
    saltotal number := 0;

begin

    open cdept;
    
    loop
        fetch cdept into pdeptno ;
        exit when cdept%notfound;
    
        open cemp(pdeptno);
         saltotal := 0;
         count1 := 0;
         count2 := 0;
         count3 :=0;
        loop
            fetch cemp into pdno,psal;
            exit when cemp%notfound;
           
            if psal < 3000 then count1 :=count1+1;
            elsif psal <= 6000 then count2:=count2+1;
            elsif psal > 6000 then count3 := count3 +1;
            end if;
            saltotal := saltotal +psal;
        end loop;
        close cemp;
        insert into msg values(pdno,count1,count2,count3,saltotal);
  end loop;


  close cdept;
  
  commit;
end;
/

案例出处：http://www.imooc.com/learn/360