以下示例显示如何将时间分成15分钟的切片。它使用分层查询。一点点解释:
trunc
函数,应用于日期值,返回当天的“开始”(午夜)。添加15 / (24*60)
需要15分钟(因为一天24小时,一小时60分钟)。乘以level
的15作为“循环”,即将15乘15乘15分钟加到之前的值。start_time
SQL> with fifteen as
2 (select trunc(sysdate) + (level * 15)/(24*60) c_time
3 from dual
4 connect by level <= (24*60) / 15
5 )
6 select to_char(c_time, 'hh24:mi') start_time,
7 to_char(c_time + 15 / (24 * 60), 'hh24:mi') end_time
8 from fifteen
9 where extract(hour from cast (c_time as timestamp)) between 10 and 15;
START_TIME END_TIME
---------- ----------
10:00 10:15
10:15 10:30
10:30 10:45
10:45 11:00
11:00 11:15
11:15 11:30
11:30 11:45
11:45 12:00
12:00 12:15
12:15 12:30
12:30 12:45
12:45 13:00
13:00 13:15
13:15 13:30
13:30 13:45
13:45 14:00
14:00 14:15
14:15 14:30
14:30 14:45
14:45 15:00
15:00 15:15
15:15 15:30
15:30 15:45
15:45 16:00
24 rows selected.
SQL>