作者：王树民ITDATA
原文：https://blog.csdn.net/wangshuminjava/article/details/80873984

一、检查并卸载MYSQL插件

rpm -qa | grep -i mysql

如果有不需要的插件执行卸载

rpm -ev ***

查找老版本mysql相关的安装目录

find / -name mysql

有则删除

rm -rf /usr/share/mysql
rm -rf /usr/lib64/mysql
rm -rf /etc/selinux/targeted/active/modules/100/mysql

最后使用命令：rpm -qa | grep -i mysql 检查系统中是否安装mysql

二、安装

shell> cd /usr/local  
shell> groupadd mysql  
shell> useradd -g mysql mysql  
shell> tar xzvf mysql-5.7.20-linux-glibc2.12-x86_64.tar.gz  
shell> cd mysql-5.7.20-linux-glibc2.12-x86_64  

这里注意了，以前的版本是有一个my.cnf文件，这个版本不要这个了
如果存在就把它删除吧，否则会出现各种错误

shell> rm -rf /etc/my.cnf    

shell> cd /usr/local  
shell> ln -s mysql-5.7.20-linux-glibc2.12-x86_64 mysql  
shell> cd /usr/local/mysql  
shell> chown -R mysql .  
shell> chgrp -R mysql .  
shell> mkdir /usr/local/mysql/data  
shell> /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data  
# 出现以下几个[Warning]不用管它，只要没有[ERROR] 就是安装成功了  
[Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).  
[Warning] InnoDB: New log files created, LSN=45790  
[Warning] InnoDB: Creating foreign key constraint system tables.  
[Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: a4d71248-c432-11e7-8eab-00163e002e4a.  
[Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.  
[Note] A temporary password is generated for root@localhost: =MqLUlnme6hh  

注意了，上面最后一行产一个随机密码，冒号后面的都是密码，我的密码则是=MqLUlnme6hh
这个随机密码第一次登录的时候需要用到

shell> chown -R root .  
shell> chown -R mysql data  

启动MySQL

shell> cd /usr/local/mysql  
shell> bin/mysqld_safe --user=mysql &  

登录并更改密码

shell> /usr/local/mysql/bin/mysql -uroot -p  

这时提示输入password，输入上面的随机密码
用随机密码登录后，必须要更改密码，否则不能进行任何操作，更改密码

mysql> SET PASSWORD = PASSWORD('newpasswd');  
mysql> exit;  

关闭MySQL服务，输入密码回车就关闭数据库

shell> /usr/local/mysql/bin/mysqladmin -u root -p shutdown  
shell> Enter password:  

编辑PATH搜索路径

shell> vi /etc/profile  

在profile文件末尾增加两行

PATH=/usr/local/mysql/bin:/usr/local/mysql/lib:$PATH  
export PATH  

使PATH搜索路径立即生效：

shell> source /etc/profile  

开机自动启动：

shell> cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql  
shell> chkconfig --add mysql  

手动启动：以root身份执行：

shell> /usr/local/mysql/bin/mysqld_safe --user=mysql &  

登录mysql，赋予root用户所有权限，远程登录密码是123456

grant all privileges on *.* to 'root' @'%' identified by '123456';  

开放3306端口并重启防火墙

firewall-cmd --permanent --add-port=3306/tcp  
firewall-cmd --reload</code>