安装步骤

1. 安装yum仓库

到https://dev.mysql.com/downloads/repo/yum/ 下载对应操作系统版本的yum仓库，然后进行安装：sudo rpm -Uvh platform-and-version-specific-package-name.rpm

2. 选择需要安装的mysql版本

默认情况下，在上一步安装的yum仓库中激活的是最新版本的MySQL，例如现在最新版本的MySQL是5.7，如下：

shell> yum repolist all | grep mysql

mysql-cluster-7.5-community/x86_64 MySQL Cluster 7.5 Community    disabled
mysql-cluster-7.5-community-source MySQL Cluster 7.5 Community -  disabled
mysql-cluster-7.6-community/x86_64 MySQL Cluster 7.6 Community    disabled
mysql-cluster-7.6-community-source MySQL Cluster 7.6 Community -  disabled
mysql-connectors-community/x86_64  MySQL Connectors Community     enabled:    42
mysql-connectors-community-source  MySQL Connectors Community - S disabled
mysql-tools-community/x86_64       MySQL Tools Community          enabled:    55
mysql-tools-community-source       MySQL Tools Community - Source disabled
mysql-tools-preview/x86_64         MySQL Tools Preview            disabled
mysql-tools-preview-source         MySQL Tools Preview - Source   disabled
mysql55-community/x86_64           MySQL 5.5 Community Server     disabled
mysql55-community-source           MySQL 5.5 Community Server - S disabled
mysql56-community/x86_64           MySQL 5.6 Community Server     disabled
mysql56-community-source           MySQL 5.6 Community Server - S disabled
mysql57-community/x86_64           MySQL 5.7 Community Server     enabled:   247
mysql57-community-source           MySQL 5.7 Community Server - S disabled
mysql80-community/x86_64           MySQL 8.0 Community Server     disabled
mysql80-community-source           MySQL 8.0 Community Server - S disabled

如果确实需要安装最新版的MySQL，那么不需要做任何修改。 如果现在需要安装的是MySQL5.6而不是最新版的5.7，那么需要执行如下操作：

shell> sudo yum-config-manager --disable mysql57-community
shell> sudo yum-config-manager --enable mysql56-community

现在再来看激活的版本是什么： 显然是5.6版本的MySQL。

shell> yum repolist all | grep mysql

mysql-cluster-7.5-community/x86_64 MySQL Cluster 7.5 Community    disabled
mysql-cluster-7.5-community-source MySQL Cluster 7.5 Community -  disabled
mysql-cluster-7.6-community/x86_64 MySQL Cluster 7.6 Community    disabled
mysql-cluster-7.6-community-source MySQL Cluster 7.6 Community -  disabled
mysql-connectors-community/x86_64  MySQL Connectors Community     enabled:    42
mysql-connectors-community-source  MySQL Connectors Community - S disabled
mysql-tools-community/x86_64       MySQL Tools Community          enabled:    55
mysql-tools-community-source       MySQL Tools Community - Source disabled
mysql-tools-preview/x86_64         MySQL Tools Preview            disabled
mysql-tools-preview-source         MySQL Tools Preview - Source   disabled
mysql55-community/x86_64           MySQL 5.5 Community Server     disabled
mysql55-community-source           MySQL 5.5 Community Server - S disabled
mysql56-community/x86_64           MySQL 5.6 Community Server     enabled:   378
mysql56-community-source           MySQL 5.6 Community Server - S disabled
mysql57-community/x86_64           MySQL 5.7 Community Server     disabled
mysql57-community-source           MySQL 5.7 Community Server - S disabled
mysql80-community/x86_64           MySQL 8.0 Community Server     disabled
mysql80-community-source           MySQL 8.0 Community Server - S disabled

3. 执行安装

shell> sudo yum install mysql-community-server

4. 启动MySQL

shell> sudo service mysqld start

启动成功之后就可以连接MySQL服务器了，使用root用户的登录不需要密码。

shell> mysql -uroot -p

当然，登录成功之后可以修改root密码：

mysql> update user set Password=password('!Q111111') where User='root';

注意，这种方式修改的root密码需要重启MySQL服务之后才能生效。

【参考】

1. https://dev.mysql.com/doc/mysql-yum-repo-quick-guide/en/