with tab as(
select 'USA,England,China,Japan'  id from dual
)
select substr(','||id||',',instr(','||id||',',',',1,level)+1,
          instr(','||id||',',',',1,level+1)-instr(','||id||',',',',1,level)-1) newid
from tab
connect by
level <= length(','||id||',') - length(replace(','||id||',', ',', ''))-1

--10g的話，用正則表達式簡單點:
with tab as(
select 'USA,England,China,Japan'  id from dual
)
select regexp_substr(id,'[^,]+',1,level) as cl1
from tab
connect by
level<=length(id)-length(replace(id,',',''))+1

------解决方案--------------------
SQL code

SQL> select regexp_substr('USA,England,China,Japan','[^,]+',1,level)
  2         as cols
  3  from dual
  4  connect by
  5          level<=length('USA,England,China,Japan')-
  6          length(replace('USA,England,China,Japan',',',''))+1;

COLS
----------------------------------------------
USA
England
China
Japan