俄罗斯奖牌的移动平均
将聚合窗口函数与帧结合使用，能够计算许多常见指标，包括移动平均和累计总和。这些指标用于跟踪随时间的表现变化。
本练习是课程的一部分
PostgreSQL 汇总统计与窗口函数
练习说明
- 计算获得奖牌数的 3 年移动平均。
交互式实操练习
通过完成这段示例代码来试试这个练习。
WITH Russian_Medals AS (
SELECT
Year, COUNT(*) AS Medals
FROM Summer_Medals
WHERE
Country = 'RUS'
AND Medal = 'Gold'
AND Year >= 1980
GROUP BY Year)
SELECT
Year, Medals,
--- Calculate the 3-year moving average of medals earned
___ OVER
(ORDER BY Year ASC
ROWS BETWEEN
___ AND ___) AS Medals_MA
FROM Russian_Medals
ORDER BY Year ASC;