PostgreSQL(WIP)

Window Function

• OVER()

Window Frames

• unbounded

• preceding

• following

• current row

Sample raw data

• default behavior is unbounded preceding

select name, sum(price) over(order by name)
from orders

same as

select name, sum(price) over(order by name range between unbounded preceding and current row)
from orders

Include current row and previous N rows

• range can only be used with unbounded

select name, sum(price) over(order by name rows between 2 preceding and current row)
from orders

select name, sum(price) over(order by name range between current row and unbounded following)
from orders

select name, sum(price) over(order by name rows between current row and 2 following)
from orders

select name, sum(price) over(order by name rows between 2 preceding and 2 following)
from orders

select name, sum(price) over(order by name range between unbounded preceding and unbounded following)
from orders

same as

select name, sum(price) over()
from orders
order by name