Questo è un bel modo, nome di fantasia "Metodo Tabibitosan " dato da Aketi Jyuuzou.
SQL> WITH data AS
2 (SELECT num - DENSE_RANK() OVER(PARTITION BY status ORDER BY num) grp,
3 status,
4 num
5 FROM t
6 )
7 SELECT MIN(num)
8 ||' - '
9 || MAX(num) range,
10 COUNT(*) cnt
11 FROM data
12 WHERE status='A'
13 GROUP BY grp
14 ORDER BY grp
15 /
RANGE CNT
------ ----------
1 - 3 3
6 - 6 1
9 - 10 2
SQL>
Nota È meglio usare DENSE_RANK per evitare duplicati.
Tabella
SQL> SELECT * FROM t ORDER BY num;
NUM S
---------- -
1 A
1 A
2 A
2 A
3 A
4 U
5 U
6 A
7 U
8 U
9 A
NUM S
---------- -
10 A
12 rows selected.
Sono presenti duplicati per num =1.
Utilizzando DENSE_RANK :
SQL> WITH data AS
2 (SELECT num - DENSE_RANK() OVER(PARTITION BY status ORDER BY num) grp,
3 status,
4 num
5 FROM t
6 )
7 SELECT MIN(num)
8 ||' - '
9 || MAX(num) range,
10 COUNT(*) cnt
11 FROM data
12 WHERE status='A'
13 GROUP BY grp
14 ORDER BY grp
15 /
RANGE CNT
------ ----------
1 - 3 5
6 - 6 1
9 - 10 2
SQL>
Utilizzando ROW_NUMBER :
SQL> WITH DATA AS
2 (SELECT num - ROW_NUMBER() OVER(PARTITION BY status ORDER BY num) grp,
3 status,
4 num
5 FROM t
6 )
7 SELECT MIN(num)
8 ||' - '
9 || MAX(num) range,
10 COUNT(*) cnt
11 FROM data
12 WHERE status='A'
13 GROUP BY grp
14 ORDER BY grp
15 /
RANGE CNT
------ ----------
2 - 3 2
1 - 2 2
1 - 6 2
9 - 10 2
SQL>
Quindi, in caso di duplicati, il ROW_NUMBER query darebbe risultati errati. Dovresti usare DENSE_RANK .
