创建一个存储过程，接受1个部门编号，利用传出参数返回月薪高于该部门平均月薪的人数。

create or replace procedure p1(p_deptno number,p_con out number)
is
begin
select count(*) into p_con
from emp
where sal > (select avg(sal) from emp where deptno = p_deptno);
end;

/

declare
v_count number(2);
begin
p1(20,v_count);
dbms_output.put_line(v_count);
end;