存储过程-声明参数并输出

create or replace procedure add_region(p_phone_num in out varchar2)
 as
 begin
   p_phone_num :='021-'||p_phone_num;
 end;

  /** ----------执行
   declare
   v_phone_num varchar2(15);
   begin
     v_phone_num := '39117380';
     add_region(v_phone_num);
     dbms_output.put_line('new phone is:'||v_phone_num);
   end;
*/