Oracle 按每天,每周,每月,每季度,每年查询统计数据

//按天统计
select count(dataid) as 每天操作数量, sum()
from tablename
group by trunc(createtime, 'DD'))
//按自然周统计 
select to_char(date,'iw'),sum() 
from  tablename
group by to_char(date,'iw')
//按自然月统计 
select to_char(date,'mm'),sum() 
from   tablename
group by to_char(date,'mm')
//按季统计 
select to_char(date,'q'),sum() 
from  tablename
group by to_char(date,'q')
//按年统计 
select to_char(date,'yyyy'),sum() 
from  tablename
group by to_char(date,'yyyy')</pre>