WINDOW FUNCTION COUNT
description
计算窗口内数据出现次数
COUNT(expression) [OVER (analytic_clause)]example
计算从当前行到第一行x出现的次数。
select x, property,
count(x) over
(
partition by property
order by x
rows between unbounded preceding and current row
) as 'cumulative total'
from int_t where property in ('odd','even');
| x | property | cumulative count |
|----|----------|------------------|
| 2 | even | 1 |
| 4 | even | 2 |
| 6 | even | 3 |
| 8 | even | 4 |
| 10 | even | 5 |
| 1 | odd | 1 |
| 3 | odd | 2 |
| 5 | odd | 3 |
| 7 | odd | 4 |
| 9 | odd | 5 |keywords
WINDOW,FUNCTION,COUNT