PostgreSQL按年月日分组（关键词：extract time as Year/Month/Day）

 

Select 

EXTRACT(year from cast(joindate as timestamp)) as Year,

EXTRACT(month from cast(joindate as timestamp)) as Month,

EXTRACT(day from cast(joindate as timestamp)) as Day,

......

From Table

Group by Year,Month,Day

Select 

EXTRACT(year from cast(joindate as timestamp)) as Year,

EXTRACT(month from cast(joindate as timestamp)) as Month,

EXTRACT(day from cast(joindate as timestamp)) as Day,

......

From Table

Group by Year,Month,Day