分组,个数

select frameIDName,count(*) from tb_chargeparsing GROUP BY frameIDName

 

时间格式转化

sqlserver

string 转 datetime

SELECT convert(datetime, '2016-10-23 20:44:11',      120) -- yyyy-mm-dd hh:mm:ss(24h)

-- 2016-10-23 20:44:11.000

SELECT convert(datetime, '2016-10-23 20:44:11.500',  121) -- yyyy-mm-dd hh:mm:ss.mmm

mysql
 --string 转 datetime
STR_TO_DATE('2021-10-22 18:56:44','%Y-%m-%d %H:%i:%s')

-- datetime 转 string
date_format(a.time,'%H:%i:%s')