昨天在itpub看到这个帖子, 问题觉得有意思,, 就仔细想了想. 也给出了一种解决办法..:-)
问题求助,请高手指点..
我有一个表结构，
fphm,kshm
,00000001
,00000002
,00000003
,00000004
,00000005
,00000007
,00000008
,00000009
,00000120
,00000121
,00000122
,00000124
,00000125
(第二个字段内可能是连续的数据，可能存在断点。)
怎样能查询出来这样的结果,查询出连续的记录来。
就像下面的这样？
,00000001,00000005
,00000009,00000007
,00000120,00000122
,00000124,00000125
方法一: 引用自hmxxyy.
SQL> select * from gap;
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
方法二: 使用lag/lead分析函数进行处理.. 楼上的方法确实挺好用就是觉得表扫描/表连接比较多, 可能数据量大了. 速度会比较慢, 当然我的这种方法由于使用分析函数使用的比较频繁.所以排序量可能比上一种要多..
SQL> select fphm,lpad(kshm,8,'0') kshm
2 from t
3 /
FPHM KSHM
---------- ----------------
00000001
00000002
00000003
00000004
00000005
00000007
00000008
00000009
00000120
00000121
00000122
FPHM KSHM
---------- ----------------
00000124
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
---------- ---------------- ----------------
00000120 00000122
00000124 00000125
00000001 00000005
00000007 00000009
SQL> spool off
方法三: 今天早上wildflower给了我这个答案, 顿时觉得耳目一新啊..就贴出来与大家一起共享了^_^.
SQL> spool aaa.log
SQL> set echo on
SQL> select * from t;
no rows selected
SQL> select * from t;
FPHM KSHM
---------- ----------
1
2
3
4
5
7
8
9
120
121
122
FPHM KSHM
---------- ----------
124
125
13 rows selected.
SQL> @bbb.sql
SQL> select b.fphm,min(b.kshm),max(b.kshm)
2 from (
3 select a.*,to_number(a.kshm-rownum) cc
4 from (
5 select * from t order by fphm,kshm
6 ) a
7 ) b
8 group by b.fphm,
9 /
FPHM MIN(B.KSHM) MAX(B.KSHM)
---------- ----------- -----------
120 122
124 125
1 5
7 9
SQL>
