WINDOW FUNCTION SUM
description
计算窗口内数据的和
SUM([ALL] expression) [OVER (analytic_clause)]example
按照 property 进行分组，在组内计算当前行以及前后各一行的x列的和。
select x, property,
sum(x) over
(
partition by property
order by x
rows between 1 preceding and 1 following
) as 'moving total'
from int_t where property in ('odd','even');
| x | property | moving total |
|----|----------|--------------|
| 2 | even | 6 |
| 4 | even | 12 |
| 6 | even | 18 |
| 8 | even | 24 |
| 10 | even | 18 |
| 1 | odd | 4 |
| 3 | odd | 9 |
| 5 | odd | 15 |
| 7 | odd | 21 |
| 9 | odd | 16 |keywords
WINDOW,FUNCTION,SUM