MySQL group query to obtain the latest data date function of each group

mysql Group query , Get the latest data of each group , If there are duplicates in the data, the latest data obtained by each group has multiple identical

select e1.* from 
(SELECT `name`,max(datatime) datatime from e_air group by `name`) e2 
left join e_air e1 on e1.`name` = e2.`name` and e1.datatime = e2.datatime

select e1.* 
from 
(SELECT `name`,max(datatime) datatime from e_air group by `name`) e2 ,e_air e1
where e1.`name` = e2.`name` and e1.datatime = e2.datatime

https://blog.csdn.net/ruanchengshen/article/details/120840215

Date function ：
date_format(‘time’, ‘%Y-%m-%d %H:%i:%s’) STR_TO_DATE(startTime,’%Y-%m-%d %H:%i:%s’)

MySQL DATE_FORMAT()：https://www.w3school.com.cn/sql/func_date_format.asp