忽略一些数据的平均计算

Question

我想计算这些数据的平均值。我不想将完成少于或等于 3 个订单的平均用户包括在内。

我使用这段代码来计算每个用户的订单总数：

SELECT DISTINCT `User`, COUNT(`User`) FROM `DB` GROUP BY`User`;

我得到结果：User1 = 9，User2 = 3，User3 = 8。我如何计算此数据的平均值，以便不考虑用户，平均值为 8.5

date                | User  | Type
-----------------------------------
17-01-2022 00:00:00 | User1 | A
17-01-2022 00:00:00 | User1 | A
17-01-2022 00:00:00 | User1 | A
17-01-2022 00:00:00 | User2 | A
18-01-2022 00:00:00 | User3 | B
18-01-2022 00:00:00 | User3 | B
18-01-2022 00:00:00 | User3 | B
19-01-2022 00:00:00 | User1 | B
19-01-2022 00:00:00 | User2 | B
19-01-2022 00:00:00 | User2 | C
19-01-2022 00:00:00 | User3 | C
20-01-2022 00:00:00 | User3 | C
20-01-2022 00:00:00 | User3 | C
20-01-2022 00:00:00 | User3 | C
20-01-2022 00:00:00 | User1 | C
21-01-2022 00:00:00 | User1 | A
21-01-2022 00:00:00 | User1 | A
21-01-2022 00:00:00 | User3 | A
21-01-2022 00:00:00 | User1 | A
21-01-2022 00:00:00 | User1 | A

Answer 1

使用HAVING子句排除订单少于或等于3个的用户，然后计算平均值：

SELECT AVG(counter) AS avg_counter
FROM (
  SELECT `User`, COUNT(`User`) AS counter
  FROM `DB` 
  GROUP BY`User`
  HAVING counter > 3
) t;

忽略一些数据的平均计算

Average calculation ignoring some data

mysql

group-by

average

count

having