Oracle 分组统计，按照天、月份周和自然周、月、季度和年

做报表统计时会经常用到 周，月，季度，年进行分组统计，所以结合网络搜索推荐的sql，总结如下

-- 按天统计
select to_char(t.CREATED+15/24, 'YYYY-MM-DD') as 天,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
group by to_char(t.CREATED+15/24, 'YYYY-MM-DD') --trunc(t.CREATED, 'DD')

-- 按自然周的日期统计 
select to_char(next_day(t.CREATED+15/24 - 7,2),'YYYY-MM-DD') AS 周,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
group by to_char(next_day(t.CREATED+15/24 - 7,2),'YYYY-MM-DD')
ORDER BY 周;

-- 按自然周统计 
select to_char(t.CREATED,'iw') AS 周,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
group by to_char(t.CREATED,'iw')
ORDER BY 周;

-- 按自然月统计 
select to_char(t.CREATED,'YYYY-MM') as 月份,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
GROUP BY
	to_char(t.CREATED,'YYYY-MM') -- to_char(t.CREATED+15/24,'yyyy-mm') 不大准确
ORDER BY 月份;

-- 按季统计 
select to_char(t.CREATED,'q') 季度,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
group by to_char(t.CREATED,'q')
ORDER BY 季度 NULLS  LAST;

--按年统计 
select to_char(t.CREATED,'yyyy') AS 年度,sum(1) as 数量
from TB_EXT_TRADE t
WHERE
	t.TID LIKE 'SC%' OR t.TID LIKE 'WSC%'
group by to_char(t.CREATED,'yyyy')
ORDER BY 年度;