1、安装前工作

卸载系统自带的Mariadb

[vagrant@master-DB ~]$ rpm -qa | grep mariadb
[vagrant@master-DB ~]$ sudo rpm -ev --nodeps  mariadb-文件全名

卸载已安装的mysql

[vagrant@master-DB ~]$ rpm -qa | grep mysql
[vagrant@master-DB ~]$ sudo rpm -ev --nodeps  mysql-文件全名

删除etc目录下的my.cnf文件

[vagrant@master-DB ~]$ sudo rm /etc/my.cnf

2、配置YUM源

在MySQL官网中下载YUM源rpm安装包

点击Download进入下载页面，复制源地址；

yum源下载地址

[vagrant@master-DB ~]$ cd /downloads
[vagrant@master-DB downloads]$ sudo wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm
[vagrant@master-DB downloads]$ ls
mysql80-community-release-el7-1.noarch.rpm
[vagrant@master-DB downloads]$ sudo rpm -Uvh mysql80-community-release-el7-1.noarch.rpm
[vagrant@master-DB downloads]$ ll /etc/yum.repos.d/ |grep mysql
-rw-r--r--. 1 root root 1864 May 30 03:17 mysql-community.repo
-rw-r--r--. 1 root root 1885 Feb 22 08:49 mysql-community-source.repo
[vagrant@master-DB downloads]$ sudo vim /etc/yum.repos.d/mysql-community.repo
[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=1
gpgcheck=1

ps:编辑 mysql-community.repo 将5.7源的enabled=0改成enabled=1，只能有一个源的enabled=1；
安装mysql

[vagrant@master-DB downloads]$ sudo yum install mysql-community-server

启动mysql并设置开机自启动

[vagrant@master-DB downloads]$ sudo systemctl start mysqld.service
[vagrant@master-DB downloads]$ sudo systemctl enable mysqld.service

查看mysql的root用户的临时密码，登入mysql并修改密码

[vagrant@master-DB downloads]$ sudo grep 'temporary password' /var/log/mysqld.log
2018-05-30T03:22:43.875508Z 1 [Note] A temporary password is generated for root@localhost: c.7rtgG+fZf%
[vagrant@master-DB downloads]$ mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.7.22 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';

附

忘记root密码并修改

• 编辑

[vagrant@master-DB ~]$ sudo vim /etc/my.cnf
[mysqld]
gtid-mode = on
enforce-gtid-consistency = 1
log-bin=mysql-bin
server_id=100
skip-grant-tables #添加这一句免密登入

• 重启mysql服务 sudo systemctl restart mysqld
• 免密登入mysql并修改密码

[vagrant@master-DB ~]$ mysql -uroot
mysql> use mysql;
mysql> update user set authentication_string=password('newpassword') where user='root';
mysql>exit;
[vagrant@master-DB ~]$ sudo vim /etc/my.cnf
[mysqld]
gtid-mode = on
enforce-gtid-consistency = 1
log-bin=mysql-bin
server_id=100
#skip-grant-tables #添加这一句免密登入

• 重启服务后就可以用新密码newpassword登入了
• 注意：mysql5.7以前 update user set authentication_string=password('newpassword') where user='root'; 中的authentication_string 替换为password