转Mysql远程链接

1、进入mysql，创建一个新用户root,密码为root：

   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 root@192.168.1.12 identified by "root";

   原先数据表结构

    mysql> use mysql;
    Database changed
    mysql> select host,user,password from user;
    +-----------+------+-------------------------------------------+
    | host      | user | password                                  |
    +-----------+------+-------------------------------------------+
    | localhost | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
    +-----------+------+-------------------------------------------+

   执行上述语句后结果

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

the article below is more useful !

How Do I Enable Remote Access To MySQL Database Server?

by Vivek Gite on March 31, 2006 · 103 comments

By default remote access to MySQL database server is disabled for security reasons. However, some time you need to provide remote access to database server from home or a web server.
MySQL Remote Access

You need type the following commands which will allow remote connections.
Step # 1: Login Using SSH (if server is outside your data center)

First, login over ssh to remote MySQL database server:

ssh [e-mail].i

Step # 2: Edit my.cnf File

Once connected you need to edit the MySQL server configuration file my.cnf using a text editor such as vi.

    * If you are using Debian Linux file is located at /etc/mysql/my.cnf location
    * If you are using Red Hat Linux/Fedora/Centos Linux file is located at /etc/my.cnf location
    * If you are using FreeBSD you need to create a file /var/db/mysql/my.cnf

Edit /etc/my.cnf, run:
# vi /etc/my.cnf
Step # 3: Once file opened, locate line that read as follows

[mysqld]

Make sure line skip-networking is commented (or remove line) and add following line

bind-address=YOUR-SERVER-IP

For example, if your MySQL server IP is 65.55.55.2 then entire block should be look like as follows:

[mysqld]
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
language        = /usr/share/mysql/English
bind-address    = 65.55.55.2
# skip-networking
....
..
....

Where,

    * bind-address : IP address to bind to.
    * skip-networking : Don’t listen for TCP/IP connections at all. All interaction with mysqld must be made via Unix sockets. This option is highly recommended for systems where only local requests are allowed. Since you need to allow remote connection this line should be removed from my.cnf or put it in comment state.

Step# 4 Save and Close the file

Restart the mysql server, enter:
# /etc/init.d/mysql restart
Step # 5 Grant access to remote IP address

Connect to mysql server:
$ mysql -u root -p mysql
Grant access to a new database

If you want to add a new database called foo for user bar and remote IP 202.54.10.20 then you need to type the following commands at mysql> prompt:mysql> CREATE DATABASE foo;
mysql> GRANT ALL ON foo.* TO bar@'202.54.10.20' IDENTIFIED BY 'PASSWORD';
How Do I Grant Access To An Existing Database?

Let us assume that you are always making connection from remote IP called 202.54.10.20 for database called webdb for user webadmin, To grant access to this IP address type the following command At mysql> prompt for existing database, enter:
mysql> update db set Host='202.54.10.20' where Db='webdb';
mysql> update user set Host='202.54.10.20' where user='webadmin';
Step # 5: Logout of MySQL

Type exit command to logout mysql:mysql> exit
Step # 6: Open port 3306

You need to open TCP port 3306 using iptables or BSD pf firewall.
A sample iptables rule to open Linux iptables firewall

/sbin/iptables -A INPUT -i eth0 -p tcp --destination-port 3306 -j ACCEPT

OR only allow remote connection from your web server located at 10.5.1.3:

/sbin/iptables -A INPUT -i eth0 -s 10.5.1.3 -p tcp --destination-port 3306 -j ACCEPT

OR only allow remote connection from your lan subnet 192.168.1.0/24:

/sbin/iptables -A INPUT -i eth0 -s 192.168.1.0/24 -p tcp --destination-port 3306 -j ACCEPT

Finally save all rules:
# service iptables save
A sample FreeBSD / OpenBSD pf rule ( /etc/pf.conf)

pass in on $ext_if proto tcp from any to any port 3306

OR allow only access from your web server located at 10.5.1.3:

pass in on $ext_if proto tcp from 10.5.1.3 to any port 3306  flags S/SA synproxy state

Step # 7: Test it

From your remote system or your desktop type the following command:
$ mysql -u webadmin –h 65.55.55.2 –p
Where,

    * -u webadmin: webadmin is MySQL username
    * -h IP or hostname: 65.55.55.2 is MySQL server IP address or hostname (FQDN)
    * -p : Prompt for password

You can also use telnet to connect to port 3306 for testing purpose:
$ telnet 65.55.55.2 3306

我的最终解决办法除了上面英文描述方法外，还有就是在用toad链接mysql时采用ssh方式，而不是tcp方式连接。