连接到MySQL数据库远程

Question

I have a MySQL database on another computer and I want to be able to connect from other computers (even computers on different networks). I did the following

MySQL

CREATE USER 'username_here'@'%' IDENTIFIED BY 'password_here';

then

GRANT ALL PRIVILEGES ON *.* TO 'username_here'@'%';
FLUSH PRIVILEGES;

I also commented out bind-address in the my.ini file (I have windows)

Then in the Java application (that utilizes the MySQL database) I did

jdbc:mysql://public_ip:3306/database_name

I used my public ip address in the jdbc url.

Finally, I opened port 3306 in firewall. But I am not able to connect to the database remotely. What other things do I need to do to connect?

Answer 1

First of all: Do not public post your real ip address and port and also say that you opened the firewall. Perhaps hackers now find it too easy to hack, but you can not rely on that ;-).

To your problem: Perhaps you configured your mysql to listen at localhost 3306 and not to your public ip address. Please enter netstat -ltn in your shell. If there is a line

tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN

and none with the public host address then you only have access from inside the network. Then, you have to configure your host adress in your mysql ini file. (just replace 127.0.0.1 or localhost by your ip address.

Answer 2

FYI : It is a very bad idea to have a publicly open port to your database server, specially MySQL default( 3306 ) port. You are just inviting people to try to break into your database.

To access MySQL remotely, follow below steps :

1) Comment out following lines in my.cnf file.

#bind-address           = 127.0.0.1
#skip-networking

2) Restart mysql server.

net stop MySQL   
net start MySQL

If you got The service name is invalid then Open task manager => Click Service button => search MySql service => Restart

Remotely connect with mysql :

mysql -h HOST -u USERNAME -pPASSWORD

You can also check the open port with nmap command :

nmap -PN Ip_address

Note : Mask your ip address in your question.

MySQL Java Connectivity :

Class.forName("com.mysql.jdbc.Driver");
// Setup the connection with the DB
Connection connection = DriverManager.getConnection("jdbc:mysql://publicIpAddress/dbName?",
                        sqluser,password);