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 = '' then  count80 := count80 +1;
     elsif phiredate = '' then  count81 := count81 +1;
     elsif phiredate = '' then  count82 := count82 +1;
     elsif phiredate = '' 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