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Connecting to MySQL from VB.net

By jvoyles ·
I have been working on an application from my PC using MySQL and VB.net. When I run the application from the PC and include in the connection string the name of the server I need to connect to I can connect without any problems. When I move the application to the server to run from there I get the exception

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

At first I figured this was because I was trying to access the MySQL database from the server instead of my PC so I put 'localhost' in the connection string and I still get this error.

I am using Studio 2005 to build the application and I am fairly new to VB.net and MySQL. Teaching myself. When the application is done I will be wanting to run it from the server with the users running it over the network and our company VPN. Is there something special I need to do in my developement to accomodate this?

I have read all the documentation for MySQL that I thought might address this issue and haven't been able to come up with anything.

Any suggestions would be helpful. The server is a Novell version 6 server if that makes any difference.

Thanks for your help.

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All Answers

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here's a link....there is a bug related to this.

by robo_dev In reply to Connecting to MySQL from ...

http://blogs.ittoolbox.com/windows/alex/archives/getting-mono-and-mysql-to-play-nice-14516

"Server=localhost;Database=test;User ID=test;Password=test;Pooling=false;Connection Timeout=10;Protocol=socket;Port=3306;"

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I had already tried this.

by jvoyles In reply to here's a link....there is ...

I found the same article before I posted my question. I have tried that work around and it didn't work.

Thanks for the link though.

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Found the solution, for me anyway.

by jvoyles In reply to here's a link....there is ...

It turned out that the exception was thrown because the server was not trusted by my .net framework. Once I made the local intranet trusted it worked.

Now my question would be is this something that will be an issue for the users as they access the program over the network? If it is then is there a way to fix it programmatically so that I can set up an install or something to change the .net configuration, making it seamless for the user?

Once again thanks for your help.

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Connections

by hamm_x_s In reply to Found the solution, for m ...

I have been developing applications using .net 2005 and MYSQL 5 (.net framework 2.0). I have never seen that kind of problem, even when connecting over a network. I simply use this connection string and I am done.

uSE THE .NET CONNECTORS

Dim myConnString As String
myConnString = "server=" & cmbServer.Text & ";" & "user id=" & txtUser.Text & ";" & "password=" & txtPassword.Text & ";" & "database=" & cmbDatabases.Text & ";"
conn.ConnectionString = myConnString
Try
conn.Open()
conn.Close()
MessageBox.Show("Permission Granted! Proceed to the system", "APPLICATION")
Dim main As New frmMain
main.connectionString = myConnString
main.Show()
Me.Hide()
Me.Close()
Catch ex As MySqlException
MessageBox.Show("Connection Error! Check options and try again " & ex.Message, "HURMIS")
Finally
conn.Dispose()
End Try

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Problem wasn't with the connection string

by jvoyles In reply to Connections

As it so often turns out with coding issues the issue isn't what we thought it was.

My problem wasn't with the connection string after all. It was with the .net security levels on my system. Changing the security level for my local intranet from medium to full allowed me to access the data.

I have since found documentation on how to set the permissions for and individual program so that I can leave the overall intranet settings at medium while I give one program full trust in the .net configuration.

Thank you all so much though for the help you have provided.

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Connecting to mysql from vb.net

by hamm_x_s In reply to Connecting to MySQL from ...

The error you are getting seems to arise from the mysql server not being active.

What connector are you using? Is it the ODBC connector or the .net connector. I encourage you to use the .net connector. It is very stable and I have not found any problem connecting from any point to another. The standard connection string is:

Dim myConnString As String
myConnString = "server=" & cmbServer.Text & ";" & "user id=" & txtUser.Text & ";" & "password=" & txtPassword.Text & ";" & "database=" & cmbDatabases.Text & ";"
conn.ConnectionString = myConnString
Try
conn.Open()
conn.Close()
MessageBox.Show("Permission Granted!", "MyProgram")
Catch ex As MySqlException
MessageBox.Show("Connection Error!" & ex.Message, "HURMIS")
Finally
conn.Dispose()
End Try
You cant go wrong with this.

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