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')