在ubuntu下载mysql-server时出现的几点问题:

• 在使用sudo apt-get install mysql-server/client或者手动解包安装时出现
  
  输入shell命令:

sudo apt-get -f install

如果无限依赖关系得不到解决可以尝试更新ubuntu源:
备份sources.list文件:

cp /etc/apt/sources.list /etc/apt/sources.list.bak

打开sources.list文件:

vi /etc/apt/sources.list

将下面的内容复制到sources.list中:

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

这里摘自 https://www.cnblogs.com/ssxblog/p/11357126.html

输入shell命令:

sudo apt-get update
sudo apt-get upgrade

• 在输入sudo apt-get install mysql-server/client 总是出现需要低版本的问题
  
  在尝试安装低版本后出现了
  
  这时先卸载mysql-common

sudo apt-get remove mysql-common

再执行:

sudo apt-get install mysql-server/client