1，sqlyog客户端，用root用户远程链接mysql时，提示“访问被拒绝”，在网上搜索了一下原因。

原来是mysql没有授权其远程链接，所以你只能在客户端里面链接。

怎么解决呢？

原表数据

mysql> use mysql

mysql> select Host,User,Password from user ;
+---------------+---------+-------------------------------------------+
| Host | User | Password |
+---------------+---------+-------------------------------------------+
| localhost | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| www | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| 127.0.0.1 | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| ::1 | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |

创建一个新用户

格式：grant 权限 on 数据库名.表名 to 用户@登录主机 identified by "用户密码";

grant select,update,insert,delete on *.* to komiles@123.4.56.89 identified by "komiles1234";

执行完上面语句后，再执行

mysql> select Host,User,Password from user ;
+---------------+---------+-------------------------------------------+
| Host | User | Password |
+---------------+---------+-------------------------------------------+
| localhost | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| www | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| 127.0.0.1 | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| ::1 | root | *DEA65ABECC50A1FEBD9C0D0D9045E0DDB312F38F |
| 123.4.56.89 | komiles | *50663F1ECEAB844897BC272EC1AE7E83F442F649 |
+---------------+---------+-------------------------------------------+

此时，就可以用你刚才创建的用户进行远程访问了。

以下是转载http://www.cnblogs.com/smallstone/archive/2010/04/29/1723838.html

2、实现远程连接(授权法)

将host字段的值改为%就表示在任何客户端机器上能以root用户登录到mysql服务器，建议在开发时设为%。   
   update user set host = ’%’ where user = ’root’;

将权限改为ALL PRIVILEGES

mysql> use mysql;
Database changed
mysql> grant all privileges  on *.* to root@'%' identified by "root";
Query OK, 0 rows affected (0.00 sec)

mysql> select host,user,password from user;
+--------------+------+-------------------------------------------+
| host         | user | password                                  |
+--------------+------+-------------------------------------------+
| localhost    | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| 192.168.1.12 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| %            | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
+--------------+------+-------------------------------------------+
3 rows in set (0.00 sec)

这样机器就可以以用户名root密码root远程访问该机器上的MySql.

3、实现远程连接（改表法）

use mysql;

update user set host = '%' where user = 'root';

这样在远端就可以通过root用户访问Mysql.