Question

我有第二个存储的一系列指标。我正在尝试制作一份能够完成以下任务的报告：

avg metric by hour
每小时最高
每小时
包括小时的日期/时间没有数据

此查询几乎产生正确的结果。但是，有几天有数据，我不希望UNION结果产生空值。我想让那些人放弃。

SELECT HOUR, METRIC, MINIMUM, MAXIMUM FROM (
select
  to_char(day,'DD-MON-YY "-" HH24":00"') AS HOUR,
  round(avg(duration), 2) AS METRIC,
  round(min(duration), 2) AS MINIMUM,
  round(max(duration), 2) AS MAXIMUM
from log_events
where day > to_date('08-NOV-10', 'DD-MON-YY')
  and day < to_date('08-NOV-10', 'DD-MON-YY') + 2
  and company = 'company A'
  and component = 'api layer'
  and event_label = 'execution request'
  group by to_char(day,'DD-MON-YY "-" HH24":00"')
  UNION
  select to_char(trunc(to_date('08-NOV-10', 'DD-MON-YY'))+(level-1)/24, 'DD-MON-YY "-" HH24":00"') HOUR,
     null as METRIC,
     null as MINIMUM,
     null as MAXIMUM
  from dual connect by level <= 48
)
order by HOUR;

我甚至不确定这是否是查询数据的正确方法。有什么建议吗？

Answer 1

使用小时创建一个内联表，然后将其连接到log_events表：

select
  dummy_hours.hour,
  log_aggregate.METRIC,
  log_aggregate.MINIMUM,
  log_aggregate.MAXIMUM
from (
  select to_char(trunc(to_date('08-NOV-10', 'DD-MON-YY'))+(level-1)/24, 'DD-MON-YY "-" HH24":00"') HOUR
  from dual connect by level <= 48
) dummy_hours, (
  select to_char(day,'DD-MON-YY "-" HH24":00"') AS HOUR,
  round(avg(duration), 2) AS METRIC,
  round(min(duration), 2) AS MINIMUM,
  round(max(duration), 2) AS MAXIMUM
  from log_events
  where day between to_date('08-NOV-10', 'DD-MON-YY') and to_date('08-NOV-10', 'DD-MON-YY') + 2
  and day > to_date('08-NOV-10', 'DD-MON-YY')
  and day < to_date('08-NOV-10', 'DD-MON-YY') + 2
  and company = 'company A'
  and component = 'api layer'
  and event_label = 'execution request'
  group by to_char(day,'DD-MON-YY "-" HH24":00"')
) log_aggregate
where dummy_hours.hour = log_aggregate.hour(+)
order by dummy_hours.hour;

从Oracle中选择没有数据日期的空日期？

1 个答案: