返回pl sql中的聚合函数

Question

如何在pl sql中返回聚合函数？

create or replace procedure get_empsalary(emp_dept varchar(20))
  as
    total_salary number(10,2);
    begin
    select sum(empsalary) 
      into total_salary 
      from employe 
     where empdept=emp_dept;
    dbms_output.put_line('department' || emp_dept || 
                         'salary is ' || total_salary);
 end;