按名称取最后一个国家
就像您可以获取数据集中第一行的值一样，您也可以获取最后一行的值。当您想把最新值与之前的值进行比较时，这通常很有用。
本练习是课程的一部分
PostgreSQL 汇总统计与窗口函数
练习说明
- 返回每届奥运会举办的年份和城市。
- 获取奥运会举办城市中的最后一个城市。
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 Hosts AS (
SELECT DISTINCT Year, City
FROM Summer_Medals)
SELECT
Year,
City,
-- Get the last city in which the Olympic games were held
___ OVER (
ORDER BY ___ ASC
RANGE BETWEEN
UNBOUNDED PRECEDING AND
UNBOUNDED FOLLOWING
) AS Last_City
FROM Hosts
ORDER BY Year ASC;