查询，计算每个季度的平均值

Question

我是MySQL的新手，需要你的帮助来找出一个查询，这样我就可以计算每个季度的平均值。我有一个名为USretail92_21的表，它看起来像这样(从1992年到2021年):

<表类> 日期 销售 tbody><<tr>1992-01-01701.01992-02-01658.01992-03-01731.01992-04-01816.01992-05-01856.01992-06-01853.01992-07-01101.01992-08-01558.01992-09-01431.0

您需要使用GROUP BY来计算总和和平均值等聚合。

参考你的例子:

WITH SalesPerMonth AS (
select year(date) as Year,
monthname(date)as Month, 
quarter(date) as Quarter, 
sales from USretail92_21 
where kind="Men's clothing stores" 
)
SELECT Quarter, Year, AVG(Sales) AS AverageSales
FROM SalesPerMonth 
GROUP BY Quarter, Year

或者一次完成:

select year(date) as Year,
quarter(date) as Quarter, 
AVG(sales) AverageSales
from USretail92_21 
where kind="Men's clothing stores"
group by year(date),
quarter(date)