mysql安装&卸载问题

ubuntu上由于mysql版本8.0连接不上，出现各种问题，将版本改为5.7

卸载

参考这个教程
https://blog.csdn.net/weixin_45525272/article/details/107774348

1.下载安装包，选择相应的版本，本次采用5.7.31

https://downloads.mysql.com/archives/community/

2.解压安装包

tar -xvf mysql-server_5.7.31-1ubuntu18.04_amd64.deb-bundle.tar

3.执行安装命令，使用sudo dpkg -i ...依次安装包，下面的命令行可能不全

sudo dpkg -i libmysqld-dev_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i libtinfo5_6.2-0ubuntu2_amd64.deb

sudo dpkg -i mysql-client_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i mysql-common_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i mysql-community-client_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i mysql-community-source_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i mysql-server_5.7.31-1ubuntu18.04_amd64.deb-bundle.tar

sudo dpkg -i mysql-common_5.7.31-1ubuntu18.04_amd64.deb

sudo dpkg -i mysql-community-client_5.7.31-1ubuntu18.04_amd64.deb

4.安装出现问题

可能会出现缺某个包，去网上搜索下载

之前安装test相关包一直报错，但是看到下面链接这里说test相关包不用安装

https://blog.csdn.net/feinifi/article/details/107406780

检查了一下可以进入

5.相关使用命令

查看端口

show global variables like 'port';