运动员奖牌的累计总数
某列的累计总数(或累计和)有助于判断每一行对总和的贡献。
本练习是课程的一部分
PostgreSQL 汇总统计与窗口函数
练习说明
- 返回运动员姓名、他们获得的奖牌数量,以及奖牌的累计总数,并按运动员姓名的字母顺序排序。
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 Athlete_Medals AS (
SELECT
Athlete, COUNT(*) AS Medals
FROM Summer_Medals
WHERE
Country = 'USA' AND Medal = 'Gold'
AND Year >= 2000
GROUP BY Athlete)
SELECT
-- Calculate the running total of athlete medals
___,
___,
___ OVER (ORDER BY ___ ASC) AS Max_Medals
FROM Athlete_Medals
ORDER BY Athlete ASC;