假如忘記了MySQL的root密碼，大家可以用以下方法重新設置：
◆1. KILL掉系統裏的MySQL進程
◆2. 用以下命令啓動MySQL，以不檢查權限的方式啓動
mysqld_safe --skip-grant-tables &
◆3. 然後用空密碼方式使用root用戶登錄 MySQL
mysql -u root
◆4. 修改root用戶的密碼
mysql> update mysql.user set password=PASSWORD('新密碼')
where User='root';
mysql> flush privileges;
mysql> quit
◆5. 重新啓動MySQL
-------------------------------------------------------
--創建用戶舉例：
GRANT SELECT , INSERT , UPDATE , DELETE , CREATE ,DROP , FILE , INDEX , ALTER , CREATE TEMPORARY TABLES, EXECUTE,ALTER ROUTINE,CREATE ROUTINE ON *.* TO 'admin'@'%'
IDENTIFIED BY 'adminpasswd'
WITH MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 ;
GRANT SELECT , INSERT , UPDATE , DELETE , CREATE , INDEX , CREATE TEMPORARY TABLES, EXECUTE ON cdrenruidb.* TO 'user'@'%'
IDENTIFIED BY 'userpasswd'
WITH MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 ;
--刪除用戶
REVOKE ALL PRIVILEGES ON * . * FROM 'user'@ '%';
DROP USER 'user'@ '%';
DROP DATABASE IF EXISTS 'user' ;