một cách để làm điều đó:
SQL> WITH DATA AS (
2 SELECT '1/01/2000' mydate, 1 GroupID, 44 Value FROM DUAL
3 UNION ALL SELECT '2/01/2000', 1, 55 FROM DUAL
4 UNION ALL SELECT '3/01/2000', 1, 66 FROM DUAL
5 UNION ALL SELECT '4/01/2000', 2, 77 FROM DUAL
6 UNION ALL SELECT '5/01/2000', 2, 88 FROM DUAL
7 UNION ALL SELECT '6/01/2000', 1, 99 FROM DUAL
8 UNION ALL SELECT '7/01/2000', 1, 22 FROM DUAL
9 )
10 SELECT mydate, groupid, VALUE
11 FROM (SELECT mydate, groupid, VALUE,
12 SUM(gap) over(ORDER BY mydate) contiguous_group
13 FROM (SELECT mydate, groupid, VALUE,
14 CASE
15 WHEN lag(groupid)
16 over(ORDER BY mydate) != groupid
17 THEN
18 1
19 ELSE
20 0
21 END gap
22 FROM DATA))
23 WHERE contiguous_group = 0;
MYDATE GROUPID VALUE
--------- ---------- ----------
1/01/2000 1 44
2/01/2000 1 55
3/01/2000 1 66
