MySQL & VB.NET

how do I link vb express with an online database and to use it in the code( now started MySQL)

I tryed it but it failed..

a vi ideo or something be nice ty

What do you want done with MySQL?

Firstly you need the .dll to reference MySQL in VB, then reference it and Import MySQL.Data.MySQLClient

Next, you need the appropriate connection string to your MySQL database:

Code:

Public SQLConnection As New MySqlConnection("server=serverIPHere;" & "user id=MySQLUsername;" & "password=databasePW;" & "database=databasename")

Then you need a connection procedure, with appropriate error handling:

Code:

    Public Sub TryConnect()

        Try
            SQLConnection.Open()
        Catch ex As Exception
            If MessageBox.Show("An error occurred when trying to connect to the database, would you like to try again?", "Database error", MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation) = Windows.Forms.DialogResult.Yes Then
                TryConnect()
            Else
                Application.Exit()
            End If
        End Try

    End Sub

And that's about it, the connection is now open. You can execute database commands such as these two:

Code:

Dim cmdStr As String = "SELECT * FROM DevStudents ORDER BY StudentName ASC"
Dim sqlCMD As New MySqlCommand(cmdStr, SQLConnection)

        Try
            Using sRead As MySqlDataReader = sqlCMD.ExecuteReader
                Do Until sRead.Read = False

                    Dim sName As String = sRead("StudentName")
                    Dim sEmail As String = sRead("Email")
                    '...rest of my procedure here, but you dont need to know that'
                Loop
        End Try

Will simply select all rows from the "DevStudents" datatable and order them in ascending order according to "StudentName" column.

This one is a non query:

Code:

Dim UpdateStr As String = "UPDATE DevStudents SET Classes='" & outstr & "' WHERE ID='" & student.ID & "'"
Dim UpdateCMD As New MySqlCommand(UpdateStr, SQLConnection)
UpdateCMD.ExecuteNonQuery()

Will update the database according to my specifications.

MySQL & VB.NET

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