天--to_char(t.start_time,‘YYYY-MM-DD‘)
周 --to_char(t.start_time,‘YYYY‘)，to_char(t.start_time,‘IW‘)
月度--to_char(t.start_time,‘YYYY-MM‘)
季度--to_char(t.start_time,‘YYYY‘)，to_char(t.start_time,‘Q‘)
年度--to_char(t.start_time,‘YYYY‘)
按天查询
select to_char(t.start_time,‘YYYY-MM-DD‘) day ,count(*) from test t
where to_char(t.start_time,‘YYYY‘)=‘2019‘ --条件限制
group by to_char(t.start_time,‘YYYY-MM-DD‘) --分组
order by to_char(t.start_time,‘YYYY-MM-DD‘) --排序
按周查询
select to_char(t.start_time,‘YYYY‘) year ,to_char(t.start_time,‘IW‘),count(*) from test t
where to_char(t.start_time,‘YYYY‘)=‘2019‘ --条件限制
group by to_char(t.start_time,‘YYYY‘) year ,to_char(t.start_time,‘IW‘)--分组
order by to_char(t.start_time,‘YYYY‘) year,to_char(t.start_time,‘IW‘) --排序
按月度查询
select to_char(t.start_time,‘YYYY-MM‘) ,count(*) from test t
where to_char(t.start_time,‘YYYY‘)=‘2019‘ --条件限制
group by to_char(t.start_time,‘YYYY-MM‘) --分组
order byto_char(t.start_time,‘YYYY-MM‘) --排序
按季度查询
select to_char(t.start_time,‘YYYY‘) year ,to_char(t.start_time,‘Q‘),count(*) from test t
where to_char(t.start_time,‘YYYY‘)=‘2019‘ --条件限制
group by to_char(t.start_time,‘YYYY‘) ,to_char(t.start_time,‘Q‘)--分组
order byto_char(t.start_time,‘YYYY‘) ,to_char(t.start_time,‘Q‘)--排序
按年度查询
select to_char(t.start_time,‘YYYY‘) year ,count(*) from test t
where to_char(t.start_time,‘YYYY‘)=‘2019‘ --条件限制
group by to_char(t.start_time,‘YYYY‘) --分组
order by to_char(t.start_time,‘YYYY‘) --排序
原文：https://blog.51cto.com/5776643/2442481