SQL 50 › 索引 › A3 Basic Aggregate Functions 基础聚合函数
LC 1211查询结果的质量和占比Queries Quality and Percentage 简单
Queries 表每次查询有位置 position 和评分 rating;求每个 query_name 的质量(rating/position 均值)与差评率(rating 小于 3 的占比百分数),保留 2 位。
思路 AVG(rating/position) 与 AVG(rating<3)*100,一次聚合两个指标。
SELECT query_name, ROUND(AVG(rating / position), 2) AS quality, ROUND(AVG(rating < 3) * 100, 2) AS poor_query_percentage FROM Queries GROUP BY query_name;