一、卸载系统自带的 Mariadb
1、查询
rpm -qa|grep mariadb
2.、卸载
rpm -e --nodeps mariadb-libs-5.5.68-1.el7.x86_64

二、下载MySQL

rpm -q glibc


三、安装步骤
1、解压安装包
mkdir -p /usr/local/mysql
tar --strip-components=1 -xvf mysql-8.0.39-linux-glibc2.17-x86_64.tar.xz -C /usr/local/mysql

2、创建MySQL组和用户
groupadd mysql
useradd -g mysql mysql

3、更改所属的组和用户
cd /usr/local
chown -R mysql mysql/
chgrp -R mysql mysql/
chown -R mysql:mysql /usr/local/mysql
cd mysql && mkdir -p data logs && chown -R mysql:mysql data logs

4、新建MySQL配置文件
vim /etc/my.cnf
[mysql]
default-character-set=utf8
[mysqld]
skip-name-resolve
port = 3306
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
max_connections=200
max_connect_errors=10
character-set-server=utf8
default-storage-engine=INNODB
default_authentication_plugin=mysql_native_password
max_allowed_packet=64M
log_error=/usr/local/mysql/logs/mysql-error.log
pid-file=/usr/local/mysql/mysql.pid
max_allowed_packet=64M
lower_case_table_names=1
chown 777 /etc/my.cnf
5、初始化MySQL
./bin/mysqld --user=mysql --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data/ --initialize

6、添加mysql服务,并设置开机自启
cp -a /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql
chmod +x /etc/rc.d/init.d/mysql
chkconfig --add mysql
chkconfig --level 345 mysql on
ln -s /usr/local/mysql/bin/mysql /usr/bin

四、启动MySQL服务
service mysql start
service mysql status
service mysql stop

五、查看临时密码,并登陆MySQL
cat /usr/local/mysql/logs/mysql-error.log

mysql -u root -p

六、修改密码
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456';
flush privileges;

七、开启远程访问
use mysql;
update user set host = '%' where user = 'root';
flush privileges;
select host, user from user;
