sql查询连续单号解决办法_Oracle开发

sql查询连续单号
我有一个表结构，
f1,f2
1,00000001
1,00000002
1,00000003
1,00000004
1,00000005
1,00000007
1,00000008
1,00000009
2,00000120
2,00000121
2,00000122
2,00000124
2,00000125

怎么得到下面的结果
2,00000001,00000005
2,00000009,00000007
1,00000120,00000122
1,00000124,00000125

------解决方案--------------------
没太看懂这个结果是怎么出来的，可否简单描述一下处理逻辑
------解决方案--------------------

SQL code

with tt as(  select 1 f1,'00000001' f2 from dual union all  select 1 f1,'00000002' f2 from dual union all  select 1 f1,'00000003' f2 from dual union all  select 1 f1,'00000004' f2 from dual union all  select 1 f1,'00000005' f2 from dual union all  select 1 f1,'00000007' f2 from dual union all  select 1 f1,'00000008' f2 from dual union all  select 1 f1,'00000009' f2 from dual union all  select 2 f1,'00000120' f2 from dual union all  select 2 f1,'00000121' f2 from dual union all  select 2 f1,'00000122' f2 from dual union all  select 2 f1,'00000124' f2 from dual union all  select 2 f1,'00000125' f2 from dual)select f1,min(f2)||','||max(f2) f2 from tt tstart with not exists(select 1 from tt where f1=t.f1 and f2=to_char(t.f2-1,'fm00000000'))connect by prior f1=f1and f2=prior to_char(f2+1,'fm00000000')group by f1,rownum-level
------解决方案--------------------
SQL code--写一个with tt as(  select 1 f1,'00000001' f2 from dual union all  select 1 f1,'00000002' f2 from dual union all  select 1 f1,'00000003' f2 from dual union all  select 1 f1,'00000004' f2 from dual union all  select 1 f1,'00000005' f2 from dual union all  select 1 f1,'00000007' f2 from dual union all  select 1 f1,'00000008' f2 from dual union all  select 1 f1,'00000009' f2 from dual union all  select 2 f1,'00000120' f2 from dual union all  select 2 f1,'00000121' f2 from dual union all  select 2 f1,'00000122' f2 from dual union all  select 2 f1,'00000124' f2 from dual union all  select 2 f1,'00000125' f2 from dual)SELECT f1, MIN(f2) || ',' || MAX(f2)  FROM (SELECT f2 - rownum gn, a.* FROM (SELECT * FROM tt ORDER BY f2) a) b GROUP BY f1, b.gn ORDER BY f1