使用MySQL yum源安装MySQL

#首先，将MySQL Yum存储库添加到系统的存储库列表中。
#在https://dev.mysql.com/downloads/repo/yum/地址中，下载mysql yum repository
[root@alone-mysql tools]# wget --no-check-certificate https://dev.mysql.com/get/mysql80-community-release-el6-3.noarch.rpm

[root@alone-mysql tools]# rpm -Uvh mysql80-community-release-el6-3.noarch.rpm 
warning: mysql80-community-release-el6-3.noarch.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing...                ########################################### [100%]
   1:mysql80-community-relea########################################### [100%]

#查看已经生效的mysql yum repository中哪些repository是启用哪些是禁用，默认是启用当前最新的mysql8
[root@alone-mysql tools]# yum repolist enabled | grep mysql       
mysql-connectors-community           MySQL Connectors Community              94
mysql-tools-community                MySQL Tools Community                   78
mysql55-community                    MySQL 5.5 Community Server             99

#这里我们需要禁用默认的mysql8，而启用mysql5.5
[root@alone-mysql tools]# yum-config-manager --disable mysql80-community
[root@alone-mysql tools]# yum-config-manager --enable mysql55-community
#再查看已经生效的mysql yum repository
[root@alone-mysql tools]# yum repolist enabled | grep mysql       
mysql-connectors-community           MySQL Connectors Community              94
mysql-tools-community                MySQL Tools Community                   78
mysql55-community                    MySQL 5.5 Community Server             487
#也可以手工对mysql-community.repo文件进行编辑，将mysql 5.5的enabled设置为1，将mysql8.0的enabled设置为0
[root@alone-mysql tools]# ls -l /etc/yum.repos.d/mysql-community.repo 
-rw-r--r--. 1 root root 2074 May 26 22:15 /etc/yum.repos.d/mysql-community.repo

#然后使用yum安装mysql
[root@alone-mysql tools]# yum install -y mysql-community-server
#启动mysql，在启动mysql的时候留意一下提示信息
[root@alone-mysql tools]# service mysqld start

#这里按照上面的提示设置一下mysql的密码
[root@alone-mysql tools]# /usr/bin/mysqladmin -u root password ‘root‘
#现在可以使用新密码登录我们的mysql
[root@alone-mysql tools]# mysql -uroot -p
Enter password: