CREATE USER <username> IDENTIFIED BY '<password>';
GRANT <PrivilegesCode> ON <dbName.tableName> TO <username>@<host> IDENTIFIED BY "<password>";
FLUSH PRIVILEGES;
SHOW GRANTS FOR '<username>';
UPDATE mysql.user SET PASSWORD=password('<NewPassword>') WHERE user = '<username>' AND host = '<host>';
FLUSH PRIVILEGES;
DROP USER <username>@'<host>'

* all privileges: 所有权限;
* select: 读取权限;
* delete: 删除权限;
* update: 更新权限;
* create: 创建权限;
* drop: 删除数据库或数据表权限;