如何使用C＃连接到远程MySQL服务器？

Question

I have a C# Application which would access a MySQL server on another computer. I am trying to do it via IP. Here is my Connection String :

server = "192.168.10.221";
database = "restaurantdb";
uid = "root";
password = "";
string connectionString;
connectionString = "SERVER=" + server + "; PORT = 3306 ;" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
mycon = new MySqlConnection(connectionString);

Now the idea is, I would connect it through the Internet or Wi-Fi connection on which both of the computers are connected to. I would then access the database through SQL Strings coded on C#. Now I could also connect them through LAN networking but I don't know how.

I am getting this exception in my code

{"Access denied for user 'root'@'Crave-PC.lan' (using password: NO)"}   System.Exception {MySql.Data.MySqlClient.MySqlException}

Any ideas how I can access the server through networking?

Answer 1

The problem is at MySQL Server side, root user doesn't have permissions to connect remotelly. To give root user permisions to connect remotelly just type this on a mysql command line:

GRANT ALL PRIVILEGES ON *.* TO root@"%" IDENTIFIED BY 'rootPass';

Just change 'rootPass' for your current root password, if root doesnt have password MySQL wont let you connect so you will have to define one for it.

One side note: As a security best practice you should define a different user other than root to access your mysql databases from client applications.

Hope it helps,

Answer 2

One addition to this thread:

In some cases where two computers are connected to the same network, the connection string defined above might still not work despite the configuration of the source computer and grant of the privileges for the user from the client computer.

In such cases, please consider (before moving further and taking more serious action on source computer such as the modification of Mysql config file etc.) to "use the computer name as the server name instead of the IP address".

ie

• first, grant the privileges to the user as described above,
• but instead of the connection string proposed above, try the following connection string:

so, the connection string would look like:

server = "pc-name-whateveritis";
database = "restaurantdb";
uid = "root";
password = "";
string connectionString;
connectionString = "SERVER=" + server + "; PORT = 3306 ;" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
mycon = new MySqlConnection(connectionString);

The name of the source computer might work in many cases the IP address of the source computer returns error.

Good luck!

Answer 3

Changing from root to a different username and set the password works well for remote access because root only have full access privileges when you are on localhost. On a local area network using an IP address gives an error so use the computer name.