我有一个如下表格，每个条目在给定时间内改变状态。 状态可以重复，因为其他列具有子状态信息。
如何按小时计算每个状态的百分比时间？
NAME STATUS_CHANGE_TIME STATUS
foo 15-MAY-11 18:52 A
foo 15-MAY-11 18:38 A
foo 15-MAY-11 18:33 B
foo 15-MAY-11 16:53 A
foo 15-MAY-11 16:47 B
foo 15-MAY-11 13:37 A
foo 15-MAY-11 13:33 C
foo 15-MAY-11 10:23 C
foo 15-MAY-11 10:17 A
foo ...
期望的回报：
HH24 STATUS PERCENT
10 ...
11 C 100 (No entries; last change was to C)
12 C 100 "" ""
13 C 62
13 A 38 (From C to A at :37 with 23 mins left; 23/60 ~ 38%)
14 A 100
15 A 100
16 A 90 (= A for first 47 minutes, then for another 7)
16 B 10 (16:53 - 16:47 = 6 minutes or 10% of an hour)
17 A 100
18 ... etc.
答案 0 :(得分：4)
很棒的问题，这是一个有趣的挑战！
您需要的是一个辅助表来存储每个时间段（在本例中为小时），然后加入到状态更新重叠的位置。 LEAD()可以抓取下一个状态条目以检查它的时间，GREATEST()和LEAST()可以确定哪个时间适用于每小时状态的开始/结束。
当然，在一个例子中解释得更容易。这是所需的HOURS表：
SQL> CREATE TABLE hours (HOUR NUMBER(2), start_m date, end_m date);
Table created.
SQL> BEGIN
2 FOR i IN 0..23 LOOP
3 INSERT INTO hours VALUES(i, to_date(lpad(i, 2, '0')||':00:00', 'HH24:MI:SS')
4 , to_date(lpad(i, 2, '0')||':59:59', 'HH24:MI:SS'));
5 END loop;
6 COMMIT;
7 END;
8 /
PL/SQL procedure successfully completed.
以下是您问题中测试数据的填充。
SQL> CREATE TABLE status_updates (NAME VARCHAR2(3), status_change_time DATE, status CHAR(1));
Table created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 18:52', 'DD-MON-RR HH24:MI:SS'), 'A');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 18:38', 'DD-MON-RR HH24:MI:SS'), 'A');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 18:33', 'DD-MON-RR HH24:MI:SS'), 'B');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 16:53', 'DD-MON-RR HH24:MI:SS'), 'A');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 16:47', 'DD-MON-RR HH24:MI:SS'), 'B');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 13:37', 'DD-MON-RR HH24:MI:SS'), 'A');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 13:33', 'DD-MON-RR HH24:MI:SS'), 'C');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 10:23', 'DD-MON-RR HH24:MI:SS'), 'C');
1 row created.
SQL> INSERT INTO status_updates VALUES ('foo',TO_DATE('15-MAY-11 10:17', 'DD-MON-RR HH24:MI:SS'), 'A');
1 row created.
SQL> commit;
Commit complete.
现在这里是select语句以获得所需的百分比。
SELECT t.NAME, t.HOUR, t.status, sum(round((status_end_h-start_status_h)*24*100)) per_cent
FROM (
SELECT A.NAME
, A.status
, A.status_change_time
, A.next_change_time
, b.HOUR
, greatest(status_change_time, trunc(status_change_time)+(b.start_m-trunc(b.start_m))) start_status_h
, least(next_change_time, trunc(next_change_time)+(b.end_m-trunc(b.end_m))) status_end_h
FROM (
SELECT NAME
, status
, status_change_time
, lead(status_change_time) OVER (ORDER BY NAME, status_change_time) next_change_time
FROM status_updates
) A, hours b
WHERE TO_CHAR(b.start_m, 'HH24:MI:SS') BETWEEN TO_CHAR(A.status_change_time, 'HH24:MI:SS') AND TO_CHAR(A.next_change_time, 'HH24:MI:SS')
OR TO_CHAR(b.end_m, 'HH24:MI:SS') BETWEEN TO_CHAR(A.status_change_time, 'HH24:MI:SS') AND TO_CHAR(A.next_change_time, 'HH24:MI:SS')
OR (TO_CHAR(A.status_change_time, 'HH24:MI:SS') BETWEEN TO_CHAR(b.start_m, 'HH24:MI:SS') AND TO_CHAR(b.end_m, 'HH24:MI:SS')
AND TO_CHAR(A.next_change_time, 'HH24:MI:SS') BETWEEN TO_CHAR(b.start_m, 'HH24:MI:SS') AND TO_CHAR(b.end_m, 'HH24:MI:SS'))
) t
GROUP BY t.NAME, t.HOUR, t.status
ORDER BY t.HOUR;
NAM HOUR S PER_CENT
--- ---------- - ----------
foo 10 A 10
foo 10 C 62
foo 11 C 100
foo 12 C 100
foo 13 A 38
foo 13 C 62
foo 14 A 100
foo 15 A 100
foo 16 A 90
foo 16 B 10
foo 17 A 100
NAM HOUR S PER_CENT
--- ---------- - ----------
foo 18 A 78
foo 18 B 8
13 rows selected.