为什么在sql developer,利用光标查询到的数据和单独查询到的数据不匹配？

–查询某个部门的员工姓名，带参数的光标

set serveroutput on;
declare
cursor cename(dno number) is select ename from emp where deptno = dno;
pename emp.ename%type;
begin
open cename(20);
loop
fetch cename into pename;
exit when cename%notfound;
end loop;
dbms_output.put_line(pename);
close cename;
end;
–只查询出一个数据
结果：
/**
FORD
**/

–观察20号部门的员工姓名，查询出了5个
select ename from emp where deptno = 20;
结果：
/**
SMITH
JONES
SCOTT
ADAMS
FORD
**/