1.查看版本 停库
[root@5haocentos ~]# cat /etc/redhat-release CentOS Linux release 7.4.1708 (Core) systemctl stop mysqld.service
2.卸载+删除
yum remove mysql mysql-server mysql-libs mysql-server
cd /var/lib/ rm -rf mysql
cd /usr/share/ rm -rf mysql/ rpm -qa |grep mysql mysql-community-release-el7-5.noarch mysql-community-common-5.7.22-1.el7.x86_64 yum remove mysql-community-release-el7-5.noarch yum remove mysql-community-common-5.7.22-1.el7.x86_64
3.备份源 安装5.6
mkdir mysql.repo.backup mv mysql-community.repo mysql-community-source.repo mysql.repo.backup/ rpm -Uvh http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm yum repolist enabled | grep "mysql.*-community.*" yum -y install mysql-community-server
4.开启数据库 并配置
systemctl start mysql.service mysql_secure_installation
依次输入
1,回车
2.y #设置密码
3.y #删除匿名用户
4. n #禁止用户远程登录
5.y # 删除test数据库
6.y #刷新权限