zyzhan

简化的上一篇下一篇sql

按小时求和SELECT sum(comment)as comment, SUM(payment_amount) as pay,DATE_FORMAT(begin_time ,'%Y-%m-%d %H') as begin_time FROM car_information GROUP BY DATE_FORMAT(begin_time ,'%Y-%m-%d %H')按分类看出现的条数SELECT *,count(*) as com FROM images WHERE img_id = 52 GRO

使用命令 lsb_release -a 查看linux发行版本 lsb_release -a输入命令 firewall-cmd --state 查看防火墙的状态firewall-cmd --statenot running 关闭running 开启开启防火墙systemctl start firewalld.service重启systemctl restart firewalld.service开启8080端口firewall-cmd --zone=public --add-p

查询日期范围关健字 betweenSELECT*FROMviolatetableWHEREcreate_time BETWEEN '2020-4-1' and '2020-06-08';```