一、卸载MySQL

1. 卸载系统自带的mariadb

   rpm -qa|grep mariadb
   rpm -e mariadb-libs --nodeps
   rpm -qa|grep mariadb
   

2. 卸载MySQL

   systemctl stop mysqld.service
   rpm -qa | grep -i mysql  
   yum remove mysql-community-libs-5.7.29-1.el7.x86_64 mysql-community-common-5.7.29-1.el7.x86_64 mysql-community-client-5.7.29-1.el7.x86_64 mysql-community-server-5.7.29-1.el7.x86_64
   rpm -qa | grep -i mysql
   find / -name mysql
   

   
   

   rm -rf /etc/my.cnf
   rm -rf /var/log/mysqld.log
   

二、安装MySQL

1. 创建MySQL目录

   mkdir /export/server/mysql
   

2. 上传压缩包到该文件夹
   
3. 解压压缩包

   tar -xvf mysql-5.7.34-1.el7.x86_64.rpm-bundle.tar
   

4. 执行安装

   yum -y install libaio
   rpm -ivh mysql-community-client-5.7.34-1.el7.x86_64.rpm mysql-community-common-5.7.34-1.el7.x86_64.rpm mysql-community-devel-5.7.34-1.el7.x86_64.rpm mysql-community-embedded-5.7.34-1.el7.x86_64.rpm mysql-community-embedded-compat-5.7.34-1.el7.x86_64.rpm mysql-community-embedded-devel-5.7.34-1.el7.x86_64.rpm mysql-community-libs-5.7.34-1.el7.x86_64.rpm mysql-community-libs-compat-5.7.34-1.el7.x86_64.rpm mysql-community-server-5.7.34-1.el7.x86_64.rpm
   

三、配置MySQL

• 初始化

  mysqld --initialize
  

• 更改所属组

  chown mysql:mysql /var/lib/mysql -R
  

• 启动MySQL

  systemctl start mysqld.service
  

• 查看生成的临时root密码

  cat  /var/log/mysqld.log
  

• 登录MySQL

  mysql -uroot -p
  临时root密码
  

• 修改root密码

  # 更新用户密码，设置为123456
  alter user user() identified by "123456";
  # 选择数据库
  use mysql;
  # 授权
  GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;
  FLUSH PRIVILEGES; 
  

• 查看、开启、关闭mysql服务

  # 查看mysql服务状态
  systemctl status mysqld
  # 关闭mysql服务
  systemctl stop mysqld
  # 查看mysql服务状态
  systemctl status mysqld
  # 开启mysql服务
  systemctl start mysqld
  # 查看mysql服务状态
  systemctl status mysqld
  

• 设置开机自动启动

  systemctl enable mysqld
  

• 查看是否设置成功

  systemctl list-unit-files | grep mysqld