我们有一个范围数据集，其中每个范围都有一个起点，终点和一个值。
create table ranges
(
range_start int not null
,range_end int not null
,range_val char(1) not null
)
;
范围可以包含其他范围或跟随另一范围，但不能等于另一范围或与另一范围相交。
这些是范围之间的有效关系：
(1) (2) (3) (4)
--------- --------- --------- -------- -----------
--- --- ---
这些关系无效：
(5) (6)
------- --------
------- --------
我们的初始范围，如果以图形方式显示，可能看起来像这样（字母代表 range_val ）：
AAAAAAAA BBCCCCCCC
DDE F GGGGG
H IIII
J
目标是获取初始范围集并在以下规则下创建新集：
包含的范围将覆盖包含范围的相应子范围。
以图形方式显示所请求的结果可能看起来像这样
ADDHAAAF BIIJIGCCC
AAAAAAAAAAAAAAAAAAAAAAAAAAAA BBBB CCCCCCCCCCCCCCCCCCCCCCCCC
DDDE FFFFFFFF GGGGGGGGG HHHHHHHH IIIIIII
JJ KKKLLL MM NN OOOOO
P QQ
insert into ranges (range_start,range_end,range_val) values (1 ,28 ,'A');
insert into ranges (range_start,range_end,range_val) values (31 ,34 ,'B');
insert into ranges (range_start,range_end,range_val) values (39 ,63 ,'C');
insert into ranges (range_start,range_end,range_val) values (1 ,3 ,'D');
insert into ranges (range_start,range_end,range_val) values (4 ,4 ,'E');
insert into ranges (range_start,range_end,range_val) values (7 ,14 ,'F');
insert into ranges (range_start,range_end,range_val) values (19 ,27 ,'G');
insert into ranges (range_start,range_end,range_val) values (43 ,50 ,'H');
insert into ranges (range_start,range_end,range_val) values (55 ,61 ,'I');
insert into ranges (range_start,range_end,range_val) values (1 ,2 ,'J');
insert into ranges (range_start,range_end,range_val) values (9 ,11 ,'K');
insert into ranges (range_start,range_end,range_val) values (12 ,14 ,'L');
insert into ranges (range_start,range_end,range_val) values (22 ,23 ,'M');
insert into ranges (range_start,range_end,range_val) values (25 ,26 ,'N');
insert into ranges (range_start,range_end,range_val) values (57 ,61 ,'O');
insert into ranges (range_start,range_end,range_val) values (13 ,13 ,'P');
insert into ranges (range_start,range_end,range_val) values (60 ,61 ,'Q');
（空格在此处显示为空格）
JJDEAAFFKKKLPLAAAAGGGMMGNNGA BBBB CCCCHHHHHHHHCCCCIIOOOQQCC
range_start range_end range_val
----------- --------- ---------
1 2 J
3 3 D
4 4 E
5 6 A
7 8 F
9 11 K
12 12 L
13 13 P
14 14 L
15 18 A
19 21 G
22 23 M
24 24 G
25 26 N
27 27 G
28 28 A
29 30
31 34 B
35 38
39 42 C
43 50 H
51 54 C
55 56 I
57 59 O
60 61 Q
62 63 C
可选添加最后一行：
64
答案 0 :(得分：1)
Oracle解决方案：
with l as ( select level lvl from dual connect by level < 66 ),
r as ( select range_start r1, range_end r2, range_val v,
range_end - range_start + 1 cnt
from ranges ),
t1 as (select distinct lvl,
nvl(max(v) keep (dense_rank first order by cnt)
over (partition by lvl), '*' ) m
from l left join r on lvl between r1 and r2 ),
t2 as (select lvl, m, case when lag(m) over (order by lvl) <> m then 0 else 1 end mrk
from t1),
t3 as (select lvl, m, lvl - sum(mrk) over (order by lvl) grp from t2)
select min(lvl) r1, max(lvl) r2, nullif(min(m), '*') val
from t3 group by grp order by r1
按要求输出。我的英语很不好，所以很难解释，但试试吧：
l - 数字生成器，r - 来自ranges的数据，距离计算t1 - 找到每个lvl的距离最小的值，t2 - 添加标记，告知范围是否开始，t3 - 添加我们将在下次使用的列
分组数据。答案 1 :(得分：1)
select new_range_start
,new_range_end
,last_value (range_val ignore nulls) over
(
partition by stack_depth
order by new_range_start ,range_start ,range_end desc
rows unbounded preceding
) as new_range_val
from (select new_range_start
,range_val
,range_start
,range_end
,sum (case when range_val is null then -1 else 1 end) over
(
order by new_range_start, range_start ,range_end desc
rows unbounded preceding
) as stack_depth
,min (new_range_start) over
(
order by new_range_start ,range_start ,range_end desc
rows between 1 following and 1 following
) - 1 as new_range_end
from ( select range_start ,range_start ,range_end ,range_val from ranges
union all select range_end + 1 ,range_start ,range_end ,cast (null as char(1)) from ranges
)
r (new_range_start,range_start,range_end,range_val)
)
r
qualify new_range_end >= new_range_start
order by new_range_start
;
select new_range_start
,new_range_end
,new_range_val
from (select new_range_start
,new_range_end
,last_value (range_val ignore nulls) over
(
partition by stack_depth
order by new_range_start ,range_start ,range_end desc
rows unbounded preceding
) as new_range_val
from (select new_range_start
,range_start
,range_end
,range_val
,sum (case when range_val is null then -1 else 1 end) over
(
order by new_range_start, range_start ,range_end desc
rows unbounded preceding
) as stack_depth
,lead (new_range_start) over
(
order by new_range_start, range_start ,range_end desc
) - 1 as new_range_end
from ( select range_start as new_range_start ,range_start ,range_end ,range_val from ranges
union all select range_end + 1 ,range_start ,range_end ,cast (null as char(1)) from ranges
)
r
)
r
)
r
where new_range_end >= new_range_start
order by new_range_start
;
select *
from (select new_range_start
,new_range_end
,min (range_val) over
(
partition by stack_depth,new_range_val_group_id
) as new_range_val
from (select new_range_start
,new_range_end
,range_val
,stack_depth
,count (range_val) over
(
partition by stack_depth
order by new_range_start ,range_start ,range_end desc
rows unbounded preceding
) as new_range_val_group_id
from (select new_range_start
,range_start
,range_end
,range_val
,sum (case when range_val is null then -1 else 1 end) over
(
order by new_range_start, range_start ,range_end desc
rows unbounded preceding
) as stack_depth
,lead (new_range_start) over
(
order by new_range_start, range_start ,range_end desc
) - 1 as new_range_end
from ( select range_start as new_range_start ,range_start ,range_end ,range_val from ranges
union all select range_end + 1 as new_range_start ,range_start ,range_end ,cast (null as char(1)) as range_val from ranges
)
r
)
r
)
r
)
r
where new_range_end >= new_range_start
order by new_range_start
;
答案 2 :(得分：0)
Oracle解决方案2
extension Array {
func tupleWithId(id: Int) -> (uniqId:Int,location:String)? {
let filteredElements = self.filter { (tuple) -> Bool in
if let tuple = tuple as? (uniqId:Int,location:String) {
return tuple.uniqId == id
}
return false
}
if filteredElements.count > 0 {
let element = filteredElements[0] as! (uniqId:Int,location:String)
return element
}
return nil
}
}
var pickerDataVisitLocation:[(uniqId:Int,location:String)] = [(203,"Home"),(204,"Hospital"),(205,"Other")]
var selectedIndex = pickerDataVisitLocation[1].uniqId
pickerDataVisitLocation.tupleWithId(id: selectedIndex)?.location
添加无自连接的解决方案： 编辑：修复缺陷。
WITH borders AS /*get all borders of interval*/
(SELECT DISTINCT DECODE(is_end, 0, range_start, range_end) AS border
,is_end
FROM ranges r,
(SELECT 0 AS is_end FROM dual UNION ALL
SELECT 1 AS is_end FROM dual)),
interv AS /*get all intervals*/
(SELECT border + is_end AS beg_int
,lead(border) over(ORDER BY border, is_end )
- lead(DECODE(is_end, 0, 1, 0)) over(ORDER BY border, is_end) AS end_int
FROM borders
ORDER BY 1)
SELECT i.beg_int
,i.end_int
,(SELECT MAX(r.range_val) keep (dense_rank FIRST ORDER BY r.range_end - r.range_start)
FROM ranges r
WHERE i.beg_int >= r.range_start AND i.end_int <= r.range_end) AS range_val
FROM interv i
WHERE beg_int <= end_int OR end_int IS NULL
ORDER BY i.beg_int;