老问题：Oracle行转列（字符串拆分）

现有以下数据：
ID Name
1 Jack,Tom,Ben
2 Mary,Simth,Tony,Jay


转换为：
ID Name
1 Jack
1 Tom
1 Ben
2 Mary
2 Simth
2 Tony
2 Jay

要求使用SQL查询完成，由于条件限制，不能使用函数，过程，游标之类的方法。
请大虾们帮忙吧！

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SQL code:
with tt as (select 1 id,'Jack,Tom,Ben' Name from dual
union all select 2,'Mary,Smith,Tony,Jay' from dual)

select a.id,
substr(','||a.name||',',instr(','||a.name,',',1,b.rn)+1,
instr(a.name||',',',',1,b.rn)-instr(','||a.name,',',1,b.rn))name
from tt a,
(select rownum rn from dual
connect by rownum<10)b
where length(a.name)-length(replace(a.name,','))+1>=b.rn
order by id,b.rn

这个10要按你的实际情况修改
不小于原表中name里项数的最大值

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with tt as ( 
select 1 id,'Jack,Tom,Ben' Name from dual 
union all select 2,'Mary,Smith,Tony,Jay' from dual 
) 
select substr(name, 
  decode(rownum, 1, 1, instr(name, ',', 1, rownum - 1)+1), 
  instr(name, ',', 1, rownum) - 
  decode(rownum, 1, 1, instr(name, ',', 1, rownum - 1)+1)) 
  from (select wmsys.wm_concat(name)||',' name from tt) a 
connect by rownum <= 5 and instr(name, ',', 1, rownu