[系统运维]Linux下MySQL的安装

MySQL的安装有多种方式，本文章只介绍yum方式的安装，如果是做自动化部署的同学，建议考虑rpm包或tar包的安装方式。

安装前检查

卸载mariadb相关包

[root@kkk ~]# rpm -qa | grep mariadb
mariadb-libs-5.5.68-1.el7.x86_64
mariadb-5.5.68-1.el7.x86_64
[root@kkk ~]# rpm -e mariadb-5.5.68-1.el7.x86_64
[root@kkk ~]# rpm -e mariadb-libs-5.5.68-1.el7.x86_64

安装mysql客户端

[root@kkk ~]# yum install -y mysql

安装mysql服务端

[root@kkk ~]# yum install -y mysql-server
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * epel: mirrors.bfsu.edu.cn
No package mysql-server available.
Error: Nothing to do

上面这个报错是因为CentOS自带mariadb，需要安装MySQL的话需要使用MySQL社区的repo文件。如果没报错，跳过这一步

[root@kkk ~]# sudo rpm -Uvh http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
Retrieving http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-release-el7-5    ################################# [100%]
[root@kkk ~]# ll /etc/yum.repos.d/mysql*
-rw-r--r-- 1 root root 1209 Jan 29  2014 /etc/yum.repos.d/mysql-community.repo
-rw-r--r-- 1 root root 1060 Jan 29  2014 /etc/yum.repos.d/mysql-community-source.repo

接下来就可以使用yum安装服务端了。

[root@kkk ~]# yum install -y mysql-server

登录MySQL

[root@kkk ~]# mysql -u root -p
Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

由于本次登录使用的socket的方法，所以需要socket文件，报错是因为没有这个文件。排查发现是安装完成后没有启动服务。（前面少了一步启动，就不往上面补了。）

[root@kkk ~]# systemctl status mysql
● mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: inactive (dead)
[root@kkk ~]# systemctl start mysql

这下就可以登录了，由于是第一次登录没有设置密码，所以密码验证可以直接回车跳过。
注：有的版本是有初始化密码的，在/var/log/mysqld.log中找到root@localhost，后面就是一个初始化密码。

[root@kkk ~]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.51 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, 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> 

设置密码

set password for root@localhost = password('root');

创建新用户，并允许远程登录

create user 'test'@'%' identified by 'test';

设置指定ip段访问

update user set host = '192.168.%.%' where user = 'test';

设置后需重启服务，或

flush privileges;