DROP USER backupuser@localhost;
CREATE USER backupuser@localhost IDENTIFIED BY 'backuppassword';
GRANT LOCK TABLES, SELECT ON *.* TO backupuser@localhost IDENTIFIED BY 'backuppassword';

mysqldump -ubackupuser -pbackuppassword --all-databases > all.sql
mysql -ubackupuser -pbackuppassword < all.sql;

CREATE USER <db_user>@localhost IDENTIFIED BY '<db_password>';
GRANT ALL privileges ON <db_name>.* TO <db_user>@localhost IDENTIFIED BY '<db_password>';