mysql -u root -p’123456’
select @@innodb_fast_shutdown;
SET GLOBAL innodb_fast_shutdown=0;
exit
mysqladmin -u root -p shutdown
tar -zxvf mysql-5.7.39-linux-glibc2.12-x86_64.tar.gz
cp -r mysql-5.7.27 mysql-5.7.27.bak
cp -frp mysql-5.7.39-linux-glibc2.12-x86_64/* mysql-5.7.27/
service mysqld restart (或者切换到相应目录 start)
mysql_upgrade -u root -p
service mysqld status