SQL查询连续号码段的巧妙解法

ID SEQ
---------- ----------
1 1
1 4
1 5
1 8
2 1
2 2
2 9

select res1.id, res2.seq str, res1.seq end
from (
select rownum rn, c.*
from (
select *
from gap a
where not exists (
select null from gap b where b.id = a.id and a.seq = b.seq - 1
)
order by id, seq
) c
) res1, (
select rownum rn, d.*
from (
select *
from gap a
where not exists (
select null from gap b where b.id = a.id and a.seq = b.seq + 1
)
order by id, seq
) d
) res2
where res1.id = res2.id
and res1.rn = res2.rn
/

ID STR END
--------- ---------- ----------
1 1 1
1 4 5
1 8 8
2 1 2
2 9 9

      FPHM KSHM                                                                
---------- ----------------                                                    
      2014 00000001                                                            
      2014 00000002                                                            
      2014 00000003                                                            
      2014 00000004                                                            
      2014 00000005                                                            
      2014 00000007                                                            
      2014 00000008                                                            
      2014 00000009                                                            
      2013 00000120                                                            
      2013 00000121                                                            
      2013 00000122                                                            

      FPHM KSHM                                                                
---------- ----------------                                                    
      2013 00000124                                                            
      2013 00000125                                                            

13 rows selected.

SQL> set echo on
SQL> @bbb.sql
SQL> select fphm,lpad(kshm,8,'0') start_kshm,lpad(prev_prev_kshm,8,'0') end_kshm
  2  from (
  3    select fphm,kshm,next_kshm,prev_kshm,
  4  lag(kshm,1,null) over (partition by fphm order by kshm )next_next_kshm,
  5  lead(kshm,1,null) over (partition by fphm order by kshm ) prev_prev_kshm
  6    from (
  7  select *
  8  from (
  9     select fphm,kshm,
10       lead(kshm,1,null) over (partition by fphm order by kshm) next_kshm,
11       lag(kshm,1,null) over (partition by fphm order by kshm) prev_kshm
12     from t
13  )
14  where ( next_kshm - kshm <> 1 or kshm - prev_kshm <> 1 )
15  or ( next_kshm is null or prev_kshm is null )
16    )
17  )
18  where next_kshm - kshm = 1
19  /

      FPHM START_KSHM       END_KSHM                                           
---------- ---------------- ----------------                                   
      2013 00000120         00000122                                           
      2013 00000124         00000125                                           
      2014 00000001         00000005                                           
      2014 00000007         00000009                                           

SQL> spool off