select regexp_substr('a,b,c,','[^,]+',1,rownum) from dual connect by rownum<=length(regexp_replace('a,b,c,', '[^,]', null));
select regexp_substr('a,b,c,','[^,]+',1,rownum) from dual connect by rownum<=length(regexp_replace('a,b,c,', '[^,]', null));