存储过程结果集怎样返回？

create or replace package pkg_test
as
type cur_test is ref cursor; -- 定義一個cursor的type
end pkg_test;
/
create or replace procedure p_test
(
v_cur out pkg_test.cur_test
)
as
v_sql varchar2(100); --
begin
v_sql := 'select a1,a2 from test';
OPEN v_cur FOR v_sql; --
exception
when others then
DBMS_OUTPUT.PUT_LINE('Error ---------------' || sqlcode || ' : ' || sqlerrm );
end p_test;
/