Oracle 求100之内的质数

大家来看看这个sql：

with t as
 (select rownum rn from dual connect by level <= 100)
select *
  from t where rn >1
minus
select ta.rn * tb.rn
  from t ta, t tb
 where ta.rn <= tb.rn
   and ta.rn > 1
   and tb.rn > 1