Oracle Function 返回单个值 (不积跬步,无以至千里)

1.

1个入参 返回值 

 function get_****t(p_deptid varchar2) return varchar2 as
    o_result varchar2(50);
  begin
    select a.emp_no || '/' || a.emp_name
      into o_result
      from employee a
     inner join **** b
        on a.emp_id = b.emp_id
     inner join **** c
        on c.id = b.dept_position_id
     inner join **** d
        on d.id = c.dept_id
     where exists (select 0
              from ****
             where form_kind = '****'
               and field_name = '****'
               and item_value = c.position_id)
       an