要求:
呼叫系统(Call Center)每天会有大量的电话进线数据，领导们要查看每天的进线数汇总，并且要求把 每天从上午8点到上午12点以及下午2点到晚上8点这两个时间段的数据汇总 “视”为当天的数据。--即分组依据
思路：把时间段折分成连续二段，一段是从当天08:00到11:59分的数据，一段是当日12:01到19:59分的数据，然后用union all合并起来，最后再用sum求和
代码
select sum(总数) 总数,时间 from (
select
count(ID) 总数,
to_char(CallDateTime,'yyyy-mm-dd') 时间
from
T_Test t
where to_char(CallDateTime,'hh24')>='08' and to_char(CallDateTime,'hh24')<='11'
group by to_char(CallDateTime,'yyyy-mm-dd')
count(ID) 总数,
to_char(CallDateTime,'yyyy-mm-dd') 时间
from
T_Test t
where to_char(CallDateTime,'hh24')>='12' and to_char(CallDateTime,'hh24')<='19'
group by to_char(CallDateTime,'yyyy-mm-dd')
)
group by 时间
order by 时间
select
count(ID) 总数,
to_char(CallDateTime,'yyyy-mm-dd') 时间
from
T_Test t
where to_char(CallDateTime,'hh24')>='08' and to_char(CallDateTime,'hh24')<='11'
group by to_char(CallDateTime,'yyyy-mm-dd')
union all
select
count(ID) 总数,
to_char(CallDateTime,'yyyy-mm-dd') 时间
from
T_Test t
where to_char(CallDateTime,'hh24')>='12' and to_char(CallDateTime,'hh24')<='19'
group by to_char(CallDateTime,'yyyy-mm-dd')
)
group by 时间
order by 时间