彙整結果
在依照 2000 年奧運各國獲得的金牌數進行排名後,你想要用一列、以逗號分隔的字串,回傳排名前 3 名的國家。換句話說,將這個:
| Country | Rank |
|---------|------|
| USA | 1 |
| RUS | 2 |
| AUS | 3 |
| ... | ... |
轉換成這個:
USA, RUS, AUS
本練習屬於課程
PostgreSQL 統計摘要與視窗函式
動手互動練習
試著完成這個範例程式碼,體驗一下這個練習。
WITH Country_Medals AS (
SELECT
Country,
COUNT(*) AS Medals
FROM Summer_Medals
WHERE Year = 2000
AND Medal = 'Gold'
GROUP BY Country)
SELECT
Country,
-- Rank countries by the medals awarded
___ AS Rank
FROM Country_Medals
ORDER BY Rank ASC;