如何找到SQL中的值的百分比？

Question

我用下面的查詢找出遊戲的英雄贏得的百分比：

SELECT Hero, (COUNT(*) * g.games) AS p 
FROM gamestatistics 
JOIN (
SELECT 100/COUNT(*) AS games 
FROM gamestatistics 
) AS g 
WHERE PointEarned>0 
GROUP BY Hero 
ORDER BY p DESC 

但是這給了我百分之所有遊戲。我想知道

percentage(for Hero)=(Won games by this player)/(Played games by this hero)

，而不是

百分比（英雄）=（該玩家贏得遊戲）/（所有遊戲）
感謝。

Answer 1

SELECT hero, AVG(pointEarned > 0) p 
FROM gamestatistics 
GROUP BY 
     hero 
ORDER BY 
     p DESC 

Answer 2

試試這個

select 
    gc.Hero, 
    sum(case when gc.PointEarned > 0 then 1 else 0 end)/count(*) as p 
from gamestatistics as gc 
group by by gc.Hero 
order by p desc 

Answer 3

使用count(HERO)代替count(*)，因爲我想它不能夠通過適當執行組。

SELECT Hero, (COUNT(HERO) * g.games) AS p 
    FROM gamestatistics 
    JOIN (
     SELECT 100/COUNT(*) AS games 
     FROM gamestatistics 
) AS g 
    WHERE PointEarned>0 
    GROUP BY Hero 
    ORDER BY p DESC; 

編輯：我相信你想sum of PointsEarned由數進行劃分。在這種情況下，查詢時幾乎沒有變化如下：

SELECT Hero, (SUM(case when PointEarned <1 then 0 else 1 end)*100/count(HERO)) AS p 
FROM gamestatistics 
GROUP BY Hero 
ORDER BY p DESC;