Oracle 如何修复解码错误？

我有以下语句需要正确，当v_变量='KP'时，将出错。任何人都可以帮忙

select *
  FROM pat_register_org_det prod
 where prod.org_code in
       decode(v_variable, 'K', '3', 'KP', '3, 6', 'PAK', '6');

select *
FROM pat_register_org_det prod
where (v_variable, prod.org_code) in 
  (('K', '3'), ('KP', '3'), ('KP', '6'), ('PAK', '6'));