每个版本可能不一样：

测试是Ubuntu 14.04版本，mysql5.7.10

官网下载wget -c http://downloads.mysql.com/archives/get/file/mysql-server_5.7.10-1ubuntu14.04_amd64.deb-bundle.tar

tar -xvf ***deb-bundle.tar 大概有10+个deb包

官网顺序http://dev.mysql.com/doc/refman/5.7/en/linux-installation-debian.html

tar -xvf mysql-server_MVER-DVER_CPU.deb-bundle.tar

sudo apt-get install libaio1

sudo dpkg-preconfigure mysql-community-server_*.deb

sudo dpkg -i mysql-{common,community-client,client,community-server,server}_*.deb

还敲了一阵sudo apt search libaio 和sudo apt install libaio1指令

后来执行sudo apt-get -f install 解决

回退5.7到5.6.21的重装过程

删除 mysql

sudo apt-get autoremove --purge mysql-server

sudo apt-get remove mysql-server

sudo apt-get autoremove mysql-server

sudo apt-get autoremove mysql-common

清理残留数据

dpkg -l |grep ^rc|awk '{print $2}' |grep mysql | sudo xargs dpkg -P

重装mysql，官网文档上的顺序

tar -xvf mysql-server_MVER-DVER_CPU.deb-bundle.tar

sudo apt-get install libaio1

sudo dpkg -i mysql-common_MVER-DVER_CPU.deb

sudo dpkg-preconfigure mysql-community-server_MVER-DVER_CPU.deb

sudo dpkg -i mysql-community-server_MVER-DVER_CPU.deb

sudo dpkg -i mysql-community-client_MVER-DVER_CPU.deb

sudo dpkg -i libmysqlclient18_MVER-DVER_CPU.deb

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sudo /etc/init.d/mysql start 服务启动

sudo /etc/init.d/mysql stop

使用户可以从其它地址可以访问服务器

首先得修改/etc/mysql/my.cnf文件，将bind-address = 127.0.0.1修改为 0.0.0.0

并赋予其访问权限grant all on *.* to root@'%' identified by "passwd"; flush privileges;

升级过程中error用：mysql_upgrade mysql -h127.0.0.1 -uroot -p123456