Centos MySQL 5.7安装、升级教程

CentOS 7上安装MySQL 5.7

MySQL 5.7是当前最新稳定版本，它的新特性包括更好的性能和可扩展性，更好的JSON支持和更大的安全性。在CentOS 7上，MySQL 5.7安装过程如下：

1. 更新系统
   在安装MySQL 5.7之前，我们需要先更新系统：

yum update -y

1. 添加MySQL Yum Repository
   下载MySQL Yum Repository Configurator并安装：

wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm
yum localinstall mysql80-community-release-el7-1.noarch.rpm -y

1. 安装MySQL
   使用yum安装MySQL 5.7：

yum install mysql-community-server -y

1. 启动MySQL
   启动MySQL服务并设置MySQL在系统启动时自动启动：

systemctl start mysqld
systemctl enable mysqld

1. 登录MySQL
   使用以下命令登录MySQL：

mysql -u root -p

1. 升级MySQL 5.7
   如果你已经安装了MySQL 5.6，并且你想升级到MySQL 5.7，请参考以下步骤：

#下载mysql57-community-release-el7-9.noarch.rpm
wget https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm

#删除mysql-community-release-el7-5.noarch.rpm
yum remove mysql-community-release-el7-5.noarch.rpm -y

#安装mysql57-community-release-el7-9.noarch.rpm
yum localinstall mysql57-community-release-el7-9.noarch.rpm -y

#卸载mysql
yum remove mysql-community-server -y

#安装mysql5.7
yum install mysql-community-server -y

#启动mysql
systemctl start mysqld

示例1：安装MySQL 5.7
假设我们的服务器是全新的，没有安装MySQL。根据上面的攻略，我们执行以下命令来安装MySQL 5.7：

yum update -y
wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm
yum localinstall mysql80-community-release-el7-1.noarch.rpm -y
yum install mysql-community-server -y
systemctl start mysqld
systemctl enable mysqld
mysql -u root -p

示例2：升级MySQL 5.7
假设我们已经安装了MySQL 5.6，现在想升级到MySQL 5.7。根据上面的攻略，我们执行以下命令来升级MySQL：

#下载mysql57-community-release-el7-9.noarch.rpm
wget https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm

#删除mysql-community-release-el7-5.noarch.rpm
yum remove mysql-community-release-el7-5.noarch.rpm -y

#安装mysql57-community-release-el7-9.noarch.rpm
yum localinstall mysql57-community-release-el7-9.noarch.rpm -y

#卸载mysql
yum remove mysql-community-server -y

#安装mysql5.7
yum install mysql-community-server -y

#启动mysql
systemctl start mysqld