Centos 7.9 安装mysql 5.7

查看是否安装过mysql，有安装过需要卸载

rpm -qa |grep mysql

卸载mysql相关

rpm -e mysql-community*

卸载系统自带的mariadb

rpm -qa|grep -i mariadb
# 并将其卸载 
rpm -e --nodeps mariadb-libs

wget 命令需先安装

wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

安装MySQL源

yum -y localinstall mysql57-community-release-el7-11.noarch.rpm

安装mysql

yum -y install mysql-community-server

systemctl start mysqld

 Failing package is: mysql-community-common-5.7.38-1.el7.x86_64
 GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
方法1：

rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

方法2：

在 yum  install后面加上 --nogpgcheck，即可绕过GPG验证成功安装。

yum install mysql-community-server --nogpgcheck

查看初始化mysql root用户密码

vim /var/log/mysqld.log

找到root@localhost:后面的密码，copy下来

mysql -u root -p

设置密码策略

SET GLOBAL validate_password_policy=LOW;
修改密码

ALTER USER 'root'@'localhost' IDENTIFIED BY 'passwd';
设置远程访问

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'passwd' WITH GRANT OPTION;
 刷新权限 

FLUSH PRIVILEGES;