查看mysql是否已安装

rpm -qa|grep mysql

若有可用 rpm -e卸载

卸载系统自带mariadb

rpm -qa|grep mariadb
yum remove -y mariadb-xxxxxxxxxxxxxxx

安装依赖libaio

libaio是Linux下的一个异步非阻塞接口，它提供了以异步非阻塞方式来读写文件的方式，读写效率比较高。

ps aux | grep libaio
ps -ef | grep libaio
没有的话，就安装：
yum install -y libaio
yum install -y cmake make gcc gcc-c++ libaio ncurses ncurses-devel

下载YUM源

wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm
rpm -ivh mysql57-community-release-el7-8.noarch.rpm
## 
rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

安装

yum -y install mysql-community-server

通过如下命令查看默认密码

 grep "temporary password" /var/log/mysqld.log

初始化

mysql_secure_installation

按照要求配置相关信息

配置my.cnf

vim /etc/my.cnf
[mysqld]
port=3306
character_set_server=utf8
init_connect='SET NAMES utf8'
#不区分大小写 
lower_case_table_names = 1
#不开启sql严格模式
sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

FAQ

忘记密码怎么办

vi /etc/my.cnf
在[mysqld]的段中加上一句：
skip-grant-tables

然后重启MySQL

systemctl restart mysqld

重新登录，免密不用输

mysql -uroot -p

选择数据库为mysql

use mysql

执行命令

update user set authentication_string=password('你的密码') where user='root';
flush privileges;

然后把/etc/my.cnf里加的skip-grant-tables删掉

重启MySQL

systemctl restart mysqld

允许弱口令(按需)

# 查看口令要求
show variables like 'validate_password%';
# 修改口令为弱口令
set global validate_password_policy=LOW;
# 修改密码长度
set global validate_password_length=6;

允许远程连接

## 必须先执行这行

update user set host = '%' where user = 'root';

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