版本选择
官方下载网址:
https://downloads.mysql.com/archives/community/
Centos可选redHat版本，也可以选择通用版（Linux—Generic）
因为此处使用.rpm文件安装，故找到mysql8.0.22的rpm包，包名如下：
三、 安装过程
1.创建文件夹mysql和mysql下的mysql-8.0.22
cd /usr/local
mkdir mysql
cd /usr/local/mysql
mkdir mysql-8.0.22
2.将rpm的tar压缩包解压到指定文件夹下
tar -xvf mysql-8.0.22-1.el7.x86_64.rpm-bundle.tar -C /usr/local/mysql
解压到/usr/local/mysql/mysql-8.0.22
3.解压完成，检查本机是否有mysql或mariadb
如果有mariadb或mysql就将其移除，不然会有冲突
查看我安装的MySQL
rpm -qa |grep mysql
卸载
rpm -ev 文件名
4.查看我安装的mariadb
rpm -qa |grep mariadb
移除已有的mysqlb版本（mysql-*）
rpm -e --nodeps mysql-community-libs-5.7.9-1.el7.x86_64
5.安装（注意安装顺序）
yum install mysql-community-common-8.0.22-1.el7.x86_64.rpm
yum install mysql-community-client-plugins-8.0.22-1.el7.x86_64.rpm
yum install mysql-community-libs-8.0.22-1.el7.x86_64.rpm
yum install mysql-community-client-8.0.22-1.el7.x86_64.rpm
yum install mysql-community-server-8.0.22-1.el7.x86_64.rpm
6.配置文件
vim /etc/my.cnf
在最下面添加
skip-grant-tables 跳过登录验证
character_set_server=utf8 设置默认字符集UTF-8
init_connect=‘SET NAMES utf8’ 设置默认字符集UTF-8
7.设置开机启动
systemctl start mysqld.service
8.启动mysql
mysql
9.开放远程连接许可
use mysql;
select host,user from user;
update user set host = ‘%’ where user = ‘root’;
flush privileges;
10.修改密码（遇到错误就重启mysql服务：systemctl restart mysqld.service）
ALTER USER ‘root’@’*’ IDENTIFIED BY ‘123456’;
flush privileges;
set global validate_password.policy=0;
set global validate_password.length=4;
ALTER USER ‘root’@’%’ IDENTIFIED WITH mysql_native_password BY ‘123456’;
11.linux下开启3306防火墙端口
firewall-cmd --zone=public --add-port=3306/tcp --permanent
systemctl restart firewalld.service