oracle plsql statistics

set serveroutput on

DECLARE

cursor cemp is select to_char(hiredate,'yyyy') from emp ;
phiredate varchar2(8);
count80 number :=0;
count81 number:=0;
count82 number:=0;
count87 number:=0;


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;
else count87:=count87+1;
end if;

end loop;
close cemp;

dbms_output.put_line('总数据:'||(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;
/