rpm -qa | grep -i mysql

service mysqld stop

rpm -ev

• 先删除server和client：

  rpm -e mysql-server mysql-client

• 删除对应的YUM源文件：

  rpm -e mysql-community-release-el6-5.noarch

• 删除相关的库文件：

  rpm -e mysql-community-common-5.6.48-2.el6.x86_64 mysql-community-libs-5.6.48-2.el6.x86_64

• 优化删除命令：

  rpm -e --nodeps

find / -name mysql
rm -rf

确保彻底删除所有相关文件和目录。

yum list installed | grep mysql

yum -y remove mysql-libs.x86_64

wget http://repo.mysql.com/mysql-community-release-el6-5.noarch.rpm

rpm -ivh mysql-community-release-el6-5.noarch.rpm

yum repolist all | grep mysql

yum -y install mysql-community-server

service mysqld start

mysql -u root

use mysql
update user set password='你的密码' where User='root';

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '你的密码' WITH GRANT OPTION;
flush privileges;
exit;

chkconfig --list | grep mysqld
chkconfig mysqld on

确保服务已开机自启动。

vi /etc/sysconfig/iptables

添加规则：

-A INPUT -p tcp --dport 3306 -j ACCEPT

service iptables restart