Centos6.5重置mysql密码并设立允许远程连接

root密码忘记，重置mysql的root密码：

一、修改mysql的配置文件my.cnf

1.在[mysqld]的段中加上一句：skip-grant-tables

[mysqld] 
datadir=/var/lib/mysql 
socket=/var/lib/mysql/mysql.sock 
skip-name-resolve 
skip-grant-tables 
保存并且退出vi。

（或执行 mysqld_safe --skip-grant-tables &）

2.重新启动mysqld 
# /etc/init.d/mysqld restart 
Stopping MySQL: [ OK ] 
Starting MySQL: [ OK ]

3.登录并修改MySQL的root密码 
# /usr/bin/mysql 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 3 to server version: 3.23.56 
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> use mysql ; 
Reading table information for completion of table and column names 
You can turn off this feature to get a quicker startup with -A

Database changed 
mysql> UPDATE user SET Password = password ( 'new-password' ) WHERE User = 'root' ; 
Query OK, 0 rows affected (0.00 sec) 
Rows matched: 2 Changed: 0 Warnings: 0

mysql> flush privileges ; 
Query OK, 0 rows affected (0.01 sec)

mysql> quit 
Bye 
4.将MySQL的登录设置修改回来 
# vi /etc/my.cnf 
将刚才在[mysqld]的段中加上的skip-grant-tables删除 
保存并且退出vi。

5．重新启动mysqld 
# /etc/init.d/mysqld restart 
Stopping MySQL: [ OK ] 
Starting MySQL: [ OK ]

二、

停止mysql服务

/etc/init.d/mysqld stop

sudo mysqld_safe --skip-grant-table&

mysql

use mysql;

update user set password = password('yourpasswd') where user = 'root';

flush privileges;

重启下mysql服务即可重新用新密码登录

/etc/init.d/mysqld restart

允许远程连接mysql

通过navicat连接MySQL的时候发生的这个错误 
ERROR 1130: Host ***.***.***.*** is not allowed to connect to this MySQL server 
说明所连接的用户帐号没有远程连接的权限，只能在本机(localhost)登录。 
需更改 MySQL 数据库里的 user表里的 host项 
把localhost改称%

一、

登陆到MySQL ，首先 use MySQL； 
按照别人提供的方式update的时候，出现错误。 
MySQL> update user set host='%' where user = 'root'; 
ERROR 1062 (23000): Duplicate entry '%-root' for key 'PRIMARY' 
然后查看了下数据库的host信息如下： 
MySQL> select host from user where user = 'root'; 
+-----------------------+ 
| host | 
+-----------------------+ 
| % | 
| 127.0.0.1 | 
| localhost.localdomain | 
+-----------------------+ 
3 rows in set (0.00 sec) 
host已经有了%这个值，所以直接运行命令：

MySQL>flush privileges;

二、

mysql> grant all privileges on *.* to 'root'@'%' withgrant option;

Query OK, 0 rows affected (0.02 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> selectuser.host from user;

+-----------+--------------+

| user| host|

+-----------+--------------+

| root| %|

| root| 127.0.0.1|

| repl_user | 192.168.1.52 |

+-----------+--------------+

3 rows in set (0.00 sec)

允许指定IP访问mysql

mysql> grant all privileges on *.* to 'root'@***.***.***.****  identified by '123456'; 
QueryOK, 0 rows affected (0.00 sec)