How to connect to MySQL database from another PC online? VB.NET

问题

Here is my connection string

mySqlCon.ConnectionString = "server=testserver.noip.me; port=3306; database=testserver1; uid=admin; pwd=admin"

I have created a vb.net application with TryCatch function to check MySql connection.

My server testserver.noip.me is a hostname of my public ip (The hostname is an example, if you check the port online, it wont work). If I change the server to localhost/127.0.0.1 or my private ip address which is something like 192.168.0.xx, the result is connected just fine. Able to connect to database even on another PC but within the same wifi network.

Whenever I change it to my public ip address or my hostname, the application returns an error message :

"Unable to connect to any of the specified MySQL hosts."

Here is the code

Try
        mySqlCon.Open()

        If mySqlCon.State = ConnectionState.Open Then
            Label5.Text = "Online"
            Label5.ForeColor = Color.GreenYellow
            LoginBtn.Enabled = True
        Else
            Label5.Text = "Offline"
            Label5.ForeColor = Color.LightPink
            LoginBtn.BackColor = Color.Red
        End If

        mySqlCon.Close()
    Catch ex As MySqlException
        If mySqlCon.State = ConnectionState.Open Then
            mySqlCon.Close()
        End If
Finally
        mySqlCon.Dispose()
    End Try

I have also done port forward in my router and the result is fine :

And the hostname port 3306 check is open as well:

Extra info : I have installed connectornet and is using MySQL workbench for this.

Everything is working fine on local network but not online. Any idea what I should do to make the application connect to the database successfully from another network online? No SSH or any secure connection guide please because this is just a test server.

回答1:

In your MYSQL (source machine) you have to enable the destination domain name for access rights. In the host table add your destination IP.

回答2:

It's Because You Did Not Forward Port.

Go to Your Router Settings, Find Port Forwarding Add A Service With HTTP, Enter Your Local IP Address, Then Specify 3306 Port As Ending Port.

This Worked For Me. Perhaps It Will For You Too.

来源：https://stackoverflow.com/questions/31739561/how-to-connect-to-mysql-database-from-another-pc-online-vb-net