刪除mysql的數(shù)據(jù)文件
sudo rm /var/lib/MySQL/ -R

刪除mysql的配置文件
sudo rm /etc/mysql/ -R

自動卸載mysql（包括server和client）
sudo apt-get autoremove mysql* --purge
sudo apt-get remove apparmor

檢查是否卸載干凈
dpkg -l | grep mysql# 若沒有返回，說明已完成卸載

dpkg --list|grep mysql  #首先在終端中查看MySQL的依賴項
sudo apt-get remove mysql-common #卸載
sudo apt-get autoremove --purge mysql-server-8.0 #卸載，看你自己安裝的什么版本在卸載
dpkg -l|grep ^rc|awk '{print$2}'|sudo xargs dpkg -P  #清除殘留數(shù)據(jù)
dpkg --list|grep mysql   #再次查看MySQL的剩余依賴項，基本到這就干凈了
sudo apt-get autoremove --purge mysql-apt-config  #如果有的話繼續(xù)刪除剩余依賴項

sudo apt update && sudo apt upgrade
sudo su #進入特權(quán)模式，使用的是root權(quán)限，這樣后續(xù)執(zhí)行命令就不需要sudo
apt install -y mysql-server #安裝的是最新版本，比如MySQL8.0的
mysql -V  #查看版本
mysql -uroot  #這種安裝方式前期沒有設(shè)置密碼，直接登錄

cat /etc/mysql/debian.cnf

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '新密碼';

dpkg -i mysql-common_8.0.20-2ubuntu20.04_amd64.deb
dpkg -i mysql-community-client-core_8.0.20-2ubuntu20.04_amd64.deb
dpkg -i mysql-community-client_8.0.20-2ubuntu20.04_amd64.deb

dpkg -i mysql-community-server-core_8.0.20-2ubuntu20.04_amd64.deb #這里應(yīng)該會報錯，缺少依賴，缺啥補啥
apt install -y libmecab2  #安裝依賴，這里是我缺的依賴
dpkg -i mysql-community-server-core_8.0.20-2ubuntu20.04_amd64.deb

dpkg -i mysql-client_8.0.20-2ubuntu20.04_amd64.deb
dpkg -i mysql-community-server_8.0.20-2ubuntu20.04_amd64.deb

mysql -V 
mysql -uroot -p123

wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-boost-5.7.18.tar.gz
tar -zxvf mysql-5.7.18.tar.gz

apt install -y cmake bison libncurses5-dev build-essential

cd mysql-5.7.18/
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql -DMYSQL_DATADIR=/usr/local/mysql/data -DWITH_BOOST=boost
make && make install

groupadd mysql
useradd -g mysql mysql
mkdir /usr/local/mysql/data
chown -R mysql /usr/local/mysql
chgrp -R mysql /usr/local/mysql

/usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data

vim /etc/my.cnf
//添加下面的內(nèi)容
[client]
socket = /tmp/mysql.sock
 
[mysqld]
port=3306
socket = /tmp/mysql.sock
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data

cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld
chmod +x /etc/init.d/mysqld
update-rc.d mysqld defaults
service mysqld start
service mysqld status #確定已經(jīng)啟動

ln -s /usr/local/mysql/bin/mysql /usr/bin/mysql
mysql -uroot -p'（udyv%Tmv0#e'

//重新修改密碼 為123456
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
exit 退出

mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;
mysql>flush privileges;
exit