Linux下卸载安装mysql

1、卸载命令：# rpm -qa |grep -i mysql 

　　# yum remove mysql-community mysql-community-server mysql-community-libs mysql-community-common

2、安装：# wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm

　　# yum localinstall mysql57-community-release-el7-8.noarch.rpm

　　# yum install mysql-community-server

3、启动 ：# systemctl start mysqld

　　重启：# systemctl restart mysqld

　　关闭：# systemctl stop mysqld

　　设置开机自启 # systemctl enable mysqld

　　　　　　　　 # systemctl daemon-reload

4、查看默认密码：# grep 'temporary password' /var/log/mysqld.log

5、登录：#  mysql -uroot -p

　　mysql> set global validate_password_length=4;  密码的长度是由validate_password_length决定的可以通过命令修改

　　mysql> set global validate_password_policy=0; validate_password_policy决定密码的验证策略,默认等级为MEDIUM(中等),可通过以下命令修改为LOW(低)

　　修改密码：mysql> set password for 'root'@'localhost'=password('123123'); 

　　添加远程账号：mysql> GRANT ALL PRIVILEGES ON *.* TO 'home'@'%' IDENTIFIED BY '123123' WITH GRANT OPTION;

7、配置默认编码utf-8：# vim /etc/my.cnf

　　添加：   character_set_server=utf8

　　　　　　init_connect='SET NAMES utf8'

8、默认配置文件路径： 

　　配置文件：/etc/my.cnf 

　　日志文件：/var/log//var/log/mysqld.log 

　　服务启动脚本：/usr/lib/systemd/system/mysqld.service 

　　socket文件：/var/run/mysqld/mysqld.pid