这个题和 “即时食物配送 I” 类似,在它那个基础上,求和除以总和
理解这个 SELECT ROUND((((5/1)+(5/2)+(1/200))/3),2) AS Demo FROM DUAL 你就离成功不远了
SELECT DISTINCT query_name,
ROUND((SUM((rating/position_q))/COUNT(query_name)),2) AS quality,
ROUND(1/COUNT(query_name)*100,2) AS poor_query_percentage
FROM Queries
GROUP BY query_name
ORDER BY quality DESC
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