mysql -h localhost -uroot -p

mysqldump -uroot -p db > db.sql

mysql -uroot -p db < db.sql
// or
mysql -uroot -p db -e "source /path/to/db.sql"

grant all privileges on ss.* to ‘root‘@‘%‘ indentified by ‘passoword‘ with grant option;
// or 
update user set Host="%" and User="root"
// 注意%是不包含localhost的
flush privileges;

CREATE USER ‘test‘@‘localhost‘ IDENTIFIED BY ‘password‘;
grant all privileges on *.* to test@‘localhost‘ identified by ‘test‘;

CREATE SCHEMA testdb DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;

GRANT ALL ON testdb.* TO ‘test‘@‘localhost‘;