mysql误删除root用户或者忘记root密码时的解决办法

一不小心删除了mysql的root用户，在网上找了很多办法都没有解决，由于mysql数据库比较多，重装又太麻烦，所以一直在努力尝试各种方法，最后终于成功了。步骤如下：

1、先结束mysqld进程

#killall mysqld

不加载grant_tables而进入mysql

#mysqld_safe --skip-grant-tables &

进入mysql#/usr/local/mysql/bin/mysqlmysql> use mysql Database changedmysql> select * from user; Empty set (0.00 sec)mysql> insert into user set user='root',ssl_cipher='',x509_issuer='',x509_subject='';               

(增加root用户的表）

Query OK, 1 row affected, 3 warnings (0.00 sec) (这时可能会提示某字段如ssl_cipher无默认值,　只要加上,ssl_cipher=''; 其字段如有提示依次添加就OK了)update user set Host='localhost',select_priv='y', insert_priv='y',update_priv='y', Alter_priv='y',delete_priv='y',create_priv='y',drop_priv='y',reload_priv='y',shutdown_priv='y',Process_priv='y',file_priv='y',grant_priv='y',References_priv='y',index_priv='y',create_user_priv='y',show_db_priv='y',super_priv='y',create_tmp_table_priv='y',Lock_tables_priv='y',execute_priv='y',repl_slave_priv='y',repl_client_priv='y',create_view_priv='y',show_view_priv='y',create_routine_priv='y',alter_routine_priv='y',create_user_priv='y' where user='root';                                        

(这里面是修改root用户的权限)

mysql> quit;

2、带权限正常启动mysql

#service mysqld start

3、使用root用户登录（如果有phpadmin就直接用root空密码登录再修改密码或权限就可以了）

#mysql -u root -p

mysql> update user set password=password('123456') where user='root';

Query OK, 1 row affected (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0mysql> flush privileges;

mysql> quit

试下没有密码时进入mysql

#mysql -u root

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

使用密码进入mysql

#mysql -u root -p 123456

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 25 to server version: 4.1.20

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>