【PL/SQL】学习笔记 （15）案例一：统计每年入职的员工人数

 1 set SERVEROUTPUT ON
 2 declare
 3     --定义光标
 4     cursor cemp is select to_char(hiredate, ‘yyyy‘) from emp;
 5     phiredate varchar2(4);
 6     --每年入职的员工人数
 7     count80 number:=0;
 8     count81 number:=0;
 9     count82 number:=0;
10     count87 number:=0;
11     
12 begin
13     --打开光标
14     open cemp;
15         loop
16           --取出一个员工的入职年份
17           fetch cemp into phiredate;
18           exit when cemp%notfound;
19           
20           --判断入职年份
21           if
22             phiredate=‘1980‘ then count80:=count80+1;
23             elsif phiredate=‘1981‘ then count81:=count81+1;
24             elsif phiredate=‘1982‘ then count82:=count82+1;
25             else count87:=count87+1;
26           end if;
27         
28         end loop;
29     --关闭光标
30     close cemp;
31     
32     --输出结果
33     dbms_output.put_line(‘Total:‘||(count80+count81+count82+count87));
34     dbms_output.put_line(‘1980:‘||count80);
35     dbms_output.put_line(‘1981:‘||count81);
36     dbms_output.put_line(‘1982:‘||count82);
37     dbms_output.put_line(‘1987:‘||count87);
38 end;
39 /