PHP和MySQL:对查询结果进行分组并取平均值

时间:2021-08-22 03:45:04

I have data in the following format:

我有以下格式的数据:

1/1/2017   55
1/3/2017   23
1/3/2017   87
1/3/2017   45
1/4/2017   77
1/4/2017   90
1/4/2017   34

What is the fasted and most efficient way to query the database and output the average value for each date?

什么是查询数据库并输出每个日期的平均值的最快和最有效的方法?

2 个解决方案

#1


3  

Your question is missing a lot of information and shows little or no effort in solving the problem.

您的问题缺少大量信息,并且很少或根本没有努力解决问题。

Regardless, you can use a SQL query like this to achieve the results you want:

无论如何,您可以使用这样的SQL查询来实现您想要的结果:

SELECT date_col, AVG(number_col) as average FROM table_name GROUP BY date_col

#2


-1  

Try this

SELECT avg(value_field) FROM `table_name` group by date _field

#1


3  

Your question is missing a lot of information and shows little or no effort in solving the problem.

您的问题缺少大量信息,并且很少或根本没有努力解决问题。

Regardless, you can use a SQL query like this to achieve the results you want:

无论如何,您可以使用这样的SQL查询来实现您想要的结果:

SELECT date_col, AVG(number_col) as average FROM table_name GROUP BY date_col

#2


-1  

Try this

SELECT avg(value_field) FROM `table_name` group by date _field