PostgreSQL 实现按年、月、日、周、时、分、秒分组统计

--按年查询
select to_char(date::DATE, 'YYYY') as year,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by year order by year

　　

--按月查询
select to_char(date::DATE, 'YYYY-MM') as month,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by month order by month

　

--按周查询
select to_char(date::DATE-(extract(dow from date::TIMESTAMP)-1||'day')::interval, 'YYYY-mm-dd') week,
sum(shares) as shares, sum(visits) as visits 
from database_table 
where date >= '2019-01-01' and  date <= '2020-01-01' group by week order by week

　　 

--按天查询
select to_char(date::DATE, 'YYYY-MM-DD') as day,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by day order by day

--按小时查询
select to_char(date::DATE, 'YYYY-MM-DD  HH24') as hour,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by hour order by hour

--按分钟查询
select to_char(date::DATE, 'YYYY-MM-DD  HH24:MI ') as minute,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by minute order by minute

--按秒查询
select to_char(date::DATE, 'YYYY-MM-DD  HH24:MI:SS ') as second,sum(shares) as shares, sum(visits) as visits 
from database_table
where date >= '2019-01-01' and  date <= '2020-01-01'  group by second order by second