请给出具体的sql或需求

给你一个思路

-- 切分合并去重
select 
      listagg(distinct regexp_substr( c1, '[^,]+', 1, level ), ',') 
           within group(order by regexp_substr( c1, '[^,]+', 1, level ))
from (

     select 'aaa,bbb,aaa,ccc,bbb' c1 from dual  -- 数据构造举例
     
) 
connect by level <= regexp_count(c1, ',') + 1;