如何平均一组的最小值

Question

如果我select每组的最小值：

SELECT MIN(price) FROM Products GROUP BY category

我怎样才能得到这个最小值的平均值？我明白

SELECT AVG(MIN(price)) FROM Products GROUP BY category

行不通。有什么帮助吗？

Answer 1

您需要分两步完成：

WITH min_prices as 
(
  SELECT category, MIN(price) as min_price 
  FROM Products 
  GROUP BY category
)
SELECT category, AVG(min_price) as avg_min_price
FROM min_prices
GROUP BY category

Answer 2

您必须找到所有类别的最小值，然后对它们应用平均函数。

select avg(m) as AvgOfAllMins from 
(
select category,min(price) as m from products
group by category) T;

查看 db-fiddle 的结果。

如何平均一组的最小值

How to average the minimums of a group by

mysql

sql

group-by