sql 按自然周,月，季度，年统计

参见兄弟的博客http://yuanyong.iteye.com/blog/451383
很不错哦。呵呵

//按自然周统计
select to_char(date,'iw'),sum()
from
where
group by to_char(date,'iw')

//按自然月统计
select to_char(date,'mm'),sum()
from
where
group by to_char(date,'mm')

//按季统计
select to_char(date,'q'),sum()
from
where
group by to_char(date,'q')

//按年统计
select to_char(date,'yyyy'),sum()
from
where
group by to_char(date,'yyyy')