安装mysql

1.卸载系统自带的mariadb-lib

• 查看mariadb版本
  rpm -qa | grep mariadb
• 卸载mariadb
  rpm -e mariadb-libs-5.5.56-2.el7.x86_64 --nodeps
• 重启机器
  reboot

[root@localhost ~]# rpm -qa | grep mariadb
mariadb-libs-5.5.52-1.el7.x86_64
[root@localhost ~]# rpm -e mariadb-libs-5.5.52-1.el7.x86_64 --nodeps
[root@localhost ~]# reboot

2.上传安装包并解压

下载地址：https://dev.mysql.com/downloads/mysql/

1. 将mysql-8.0.18-1.el8.x86_64.rpm-bundle.tar安装包上传到/opt/software目录

   • 先在opt下面创建software文件夹

     [root@localhost /]# cd /opt
     [root@localhost opt]# mkdir software
     

   linux中/opt目录用来安装附加软件包，是用户级的程序目录，可以理解为D:/Software。安装到/opt目录下的程序，它所有的数据、库文件等等都是放在同个目录下面。

   • 上传到software这个文件夹

     [root@localhost opt]# cd software/
     [root@localhost software]# rz
     [root@localhost software]# ls
     mysql-8.0.26-1.el8.x86_64.rpm-bundle.tar
     

2. 解压mysql安装包到/opt/server目录

   [root@localhost opt]# mkdir server
   [root@localhost opt]# cd software/
   [root@localhost software]# tar -xvf  mysql-8.0.26-1.el8.x86_64.rpm-bundle.tar -C /opt/server
   

3. 按顺序安装

   进入server文件夹进行顺序安装

   [root@localhost software]# cd ../server
   [root@localhost server]# ls
   mysql-community-client-8.0.26-1.el8.x86_64.rpm
   mysql-community-client-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-client-plugins-8.0.26-1.el8.x86_64.rpm
   mysql-community-client-plugins-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-common-8.0.26-1.el8.x86_64.rpm
   mysql-community-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-debugsource-8.0.26-1.el8.x86_64.rpm
   mysql-community-devel-8.0.26-1.el8.x86_64.rpm
   mysql-community-libs-8.0.26-1.el8.x86_64.rpm
   mysql-community-libs-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-server-8.0.26-1.el8.x86_64.rpm
   mysql-community-server-debug-8.0.26-1.el8.x86_64.rpm
   mysql-community-server-debug-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-server-debuginfo-8.0.26-1.el8.x86_64.rpm
   mysql-community-test-8.0.26-1.el8.x86_64.rpm
   mysql-community-test-debuginfo-8.0.26-1.el8.x86_64.rpm
   

   必须安装(注意顺序)

   [root@localhost server]# rpm -ivh mysql-community-common-8.0.26-1.el8.x86_64.rpm 
   

   rpm -ivh mysql-community-libs-8.0.13-1.el7.x86_64.rpm
   

   

   在命令后面加上--force --nodeps即可

   [root@localhost server]# rpm -ivh mysql-community-libs-8.0.26-1.el8.x86_64.rpm --force --nodeps
   

   同理，都要加上否则报错

   [root@localhost server]# rpm -ivh mysql-community-client-8.0.26-1.el8.x86_64.rpm --force --nodeps
   
   [root@localhost server]# rpm -ivh mysql-community-server-8.0.26-1.el8.x86_64.rpm  --force --nodeps
   
   

   非必要安装（注意顺序）我这里面没有，就不安装了

   rpm -ivh mysql-community-libs-compat-8.0.13-1.el7.x86_64.rpm
   rpm -ivh mysql-community-embedded-compat-8.0.13-1.el7.x86_64.rpm
   rpm -ivh mysql-community-devel-8.0.13-1.el7.x86_64.rpm
   rpm -ivh mysql-community-test-8.0.13-1.el7.x86_64.rpm
   

4. 启动数据库

   [root@localhost server]# service mysqld start
   

   此时显示Redirecting to /bin/systemctl start mysqld.service
   Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

   初始化数据库

   service mysqld start

   但是出错了,上网参考了这个 ：https://blog.csdn.net/LiMarrtin/article/details/110281420

   查看rpm -qa|grep mariadb,空的不用删除

   依然报错

   [root@localhost mysql]# rm -rf /var/lib/mysql
   [root@localhost mysql]# service mysqld restart
   Redirecting to /bin/systemctl restart  mysqld.service
   Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
   
   

   检查

   [root@localhost mysql]# systemctl status mysqld.service
   ● mysqld.service - MySQL Server
      Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
      Active: failed (Result: start-limit) since 日 2021-08-01 14:33:22 CST; 48s ago
        Docs: man:mysqld(8)
              http://dev.mysql.com/doc/refman/en/using-systemd.html
     Process: 99347 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS (code=exited, status=127)
     Process: 99317 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
    Main PID: 99347 (code=exited, status=127)
   
   8月 01 14:33:22 localhost.localdomain systemd[1]: mysqld.service: main process exited, code=exited, status=127/n/a
   8月 01 14:33:22 localhost.localdomain systemd[1]: Failed to start MySQL Server.
   8月 01 14:33:22 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
   8月 01 14:33:22 localhost.localdomain systemd[1]: mysqld.service failed.
   8月 01 14:33:22 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
   8月 01 14:33:22 localhost.localdomain systemd[1]: start request repeated too quickly for mysqld.service
   8月 01 14:33:22 localhost.localdomain systemd[1]: Failed to start MySQL Server.
   8月 01 14:33:22 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
   8月 01 14:33:22 localhost.localdomain systemd[1]: mysqld.service failed.
   
   

   卸载mysql

   1、查看

   [root@localhost opt]# rpm -qa |grep -i mysql
   mysql-community-libs-8.0.26-1.el8.x86_64
   mysql-community-common-8.0.26-1.el8.x86_64
   mysql-community-client-8.0.26-1.el8.x86_64
   mysql-community-server-8.0.26-1.el8.x86_64
   
   

   2、yum remove 卸载

   yum remove mysql-community-client.x86_64 
   yum remove mysql-community-common.x86_64 
   
   

   卸载两个即可

   3、检查卸载干净与否

   [root@localhost opt]#  find / -name mysql
   /etc/selinux/targeted/active/modules/100/mysql
   /usr/lib64/mysql
   /opt/software/mysql
   

   挨个删除

   [root@localhost opt]#  rm -rf /etc/selinux/targeted/active/modules/100/mysql
   [root@localhost opt]#  rm -rf /usr/lib64/mysql
   [root@localhost opt]# rm -rf /opt/software/mysql
   
   

   mysqld --initialize --console

   使用yum安装mysql

   1、https://dev.mysql.com/downloads/repo/yum/

   

   2、下载后上传到/opt

   [root@localhost opt]# rz
   [root@localhost opt]# ls
   mysql80-community-release-el7-3.noarch.rpm
   

   3、 安装yum源

   [root@localhost opt]# yum -y localinstall mysql80-community-release-el7-3.noarch.rpm 
   
   

   4、在线安装

   yum -y install mysql-community-server
   

   报错：发现 13 个已存在的 RPM 数据库问题， 'yum check' 输出如下：
   mysql-community-libs-8.0.26-1.el8.x86_64 有缺少的需求 libc.so.6(GLIBC_2.28)(64bit)
   mysql-community-libs-8.0.26-1.el8.x86_64 有缺少的需求 libcrypto.so.1.1()(64bit)
   mysql-community-libs-8.0.26-1.el8.x86_64 有缺少的需求 libcrypto.so.1.1(OPENSSL_1_1_0)(64bit)
   mysql-community-libs-8.0.26-1.el8.x86_64 有缺少的需求 libcrypto.so.1.1(OPENSSL_1_1_1)(64bit)

   使用 yum 搜索 已经安装软件

   yum list installed
   

   删除掉已安装的

   yum remove mysql-community-common.x86_64
   

   然后重新

   yum -y install mysql-community-server
   

   

   [root@localhost opt]# service mysqld start
   Redirecting to /bin/systemctl start  mysqld.service
   

   执行完service mysqld start之后，系统没有像以往那样提示"启动成功"，但，通过命令systemctl status mysqld查询mysql服务状态，发现mysql服务已经启动成功

   

5. 初始化数据库

   mysqld --initialize --console
   

6. 目录授权，否则启动失败

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

7. 启动msyql服务

   systemctl start mysqld
   

   

8. 在/var/log/mysqld.log下查看临时密码

   cat /var/log/mysqld.log
   

   

9. 用临时密码登录到数据库

   • mysql -u root -p + 回车键

   • 输入临时密码（输入时不会显示出来，输入完直接回车）

     [root@localhost opt]# mysql -u root -pM/k%A4nu6ZWV
     

10. 执行下列mysql命令 修改密码
    alter USER 'root'@'localhost' IDENTIFIED BY '新密码';

    (新密码：必须包含：数字大小写字母特殊字符)

    mysql> alter USER 'root'@'localhost' IDENTIFIED BY 'root@123ROOT';
    Query OK, 0 rows affected (0.00 sec)
    

11. 依次执行下列mysql命令 授权远程连接

    • 查看所有用户是否可以远程连接，依次执行下列命令：
      show databases;
use mysql;
select host, user, authentication_string, plugin from user;
    

    host为localhsot，说明用户只能本地连接msyql服务

    • 修改root用户host值，使root用户可以远程登录
      update user set host = "%" where user='root';

      

    • 刷新
      flush privileges;

    • 退出

      mysql> quit
      Bye
      

    • 远程登录到其他人的mysql

      mysql --host=ip地址 --user=用户名 --password = 密码