如何使用 ADO.NET 将我的 vb.net 项目连接到 mariadb？

Question

我有这个模块来处理连接到我的数据库的连接字符串：

Module DBCONNECTION
    Public myGlobalConnectionString As String
    Public Sub Main()

        Dim sDataserver As String
        Dim sDatabaseName As String
        Dim sDatabaseConnection As String
        Try
           sDataserver = "localhost"
           sDatabaseName = "Student"

           sDatabaseConnection  = ("Driver={MariaDB ODBC 3.1 Driver};SERVER=" & sDataserver & ";USER=root;PASSWORD=****;DATABASE=" & sDatabaseName & ";PORT=3306")
           sDatabaseConnection = myGlobalConnectionString 
       Catch ex As Exception
           MessageBox.Show(ex.Message)
    End Try
  End Sub
End Module

我有这个 class 将打开和关闭myGlobalConnectionString的连接

Public Shared Sub OpenDb()
    Dim con = New OleDb.OleDbConnection
    con.ConnectionString = myGlobalConnectionString
    con.Open() // when it tried to open, the error appear
End Sub
Public Shared Sub CloseDb()
    Dim con = New OleDb.OleDbConnection
    If Not con Is Nothing Then
        con.Close()
        con = Nothing
    End If
End Sub

和我的表格

Private Sub LoginForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim con As New clsDataQuery
    con.OpenDb()
End Sub

我收到这个错误

System.InvalidOperationException: 'ConnectionString 属性尚未初始化。'

如何修复此错误？