run_sql.sql

declare
  v_error_message varchar2(4000);

  function is_empty_field(p_field_name in varchar2, p_field_value in varchar2, p_error_message out varchar2)
  return boolean is
  begin
      IF p_field_value is not null then
          p_error_message := 'заполнено поле "'||p_field_name||'"';
          return true;
      end if;
      return false;
  end;
begin
  if not is_empty_field('№1',  to_char(9), v_error_message) then
    -- Attention!  Will not work!
    dbms_output.put_line(v_error_message);
  end if;
--  dbms_output.put_line(v_error_message);
end;