Oracle获取拆分项

Oracle把逗号分割的字符串转换为可放入in的条件语句的字符数列
前台传来的字符串：'589,321' 

SELECT
*
FROM TAB_A T1 
WHERE  T1.CODE  IN (

SELECT REGEXP_SUBSTR('589,321','[^,]+', 1, LEVEL) FROM DUAL

CONNECT BY REGEXP_SUBSTR('SMITH,ALLEN,WARD,JONES', '[^,]+', 1, LEVEL) IS NOT NULL

)