问题现象

数据库 MySQL 的 user 授权表默认有三条 root 账号记录，如图：

如操作误删除，同时没有正确插入，再次登陆 MySQL 会报错如下：

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

启动到安全模式下重新授权也无法成功登陆，因安全模式已经跳过授权表，报错如下：

ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

处理办法

可参考如下步骤处理，建议在操作前创建磁盘快照进行备份，避免操作失误后可以迅速恢复。

1、修改 MySQL 配置文件启动到安全模式下：

# vi /etc/my.cnf

注意：以实际 MySQL 配置文件 my.cnf 路径为准。

在[mysqld]的段中加上一句：skip-grant-tables 保存并退出 vi 编辑器，重新启动 mysqld ：

# /etc/init.d/mysqld restart

2、登陆 MySQL ，并重新插入

#/usr/bin/mysql
#use mysql；

密码用password函数加密，比如密码为“aliyun“：

#mysql> select password('aliyun');

#mysql> insert into user (host,user,Password,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv,Reload_priv,Shutdown_priv,Process_priv,File_priv,Grant_priv,References_priv,Index_priv,Alter_priv,Show_db_priv,Super_priv,Create_tmp_table_priv,Lock_tables_priv,Execute_priv,Repl_slave_priv,Repl_client_priv,Create_view_priv,Show_view_priv,Create_routine_priv,Alter_routine_priv,Create_user_priv,Event_priv,Trigger_priv,max_questions,max_updates,max_connections,max_user_connections) values ("localhost","root","*2411E566C2C7E14C6946F80619D4BE802887A4DB","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","Y","0","0","0","0");

#flush privileges;
#quit

3、打开 MySQL 配置文件，注释“skip-grant-tables” ，保存并退出。

重启 MySQL 后测试登陆正常：

#/etc/init.d/mysqld restart 
#mysql -uroot -paliyun