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')

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

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

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

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

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

 create table CONSUMER_ACC 
 ( 
 ID VARCHAR2(50) not null , 
 ACC_NUM VARCHAR2(10), 
 DATETIME DATE 
 ) 

 select t.id,trunc(t.datetime, 'mm' ) as d, sum (t.acc_num) as n 
 from CONSUMER_ACC t 
 --where 
 group by t.id,trunc(t.datetime, 'mm' ) 
 order by n desc ; 
 select t.id,to_char(t.datetime, 'mm' ) d , sum (t.acc_num) n 
 from CONSUMER_ACC t 
 --where 
 group by t.id,to_char(t.datetime, 'mm' ) 
 order by n desc 
------------------------------------------------------------------------------
//按天统计  
select count(dataid) as 每天操作数量, sum() 
from 
where 
group by trunc(createtime, 'DD')) 
//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')