https://blog.csdn.net/xxd851116/article/details/22947891https://blog.csdn.net/u012286517/article/details/50436740/https://blog.csdn.net/sikefeng/article/details/79597273
GRANT Select ON *.* TO dbreader@"%" IDENTIFIED BY "Devsdf018";
mysql -u root
flush privileges;
service mysqld restart
service mysqld status
service mysqld start
service mysqld stop
vi /etc/my.cnf
use mysql;
show databases;
UPDATE user SET Password=PASSWORD('sdfdfd42018') where USER='root';
set password for root@localhost=password('sdfds3d42018');
