codice:
'libreria per usare mysql
Imports MySql.Data.MySqlClient

Public Class classi

    Public Sub connessione()

        Dim ServerString As String = "Server=localhost;User Id=root;Password=password;Database=db"

        Dim SQLConnection As MySqlConnection = New MySqlConnection

        SQLConnection.ConnectionString = ServerString
        Try
            If SQLConnection.State = ConnectionState.Closed Then
                SQLConnection.Open()
                'MsgBox("Connessione con il server effettuata con successo")

            Else
                SQLConnection.Close()
                MsgBox("Error. Control connection parameter")
            End If

        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try

    End Sub

    Public Shared Function ExecuteNonQuery(ByRef sql) As Boolean

        Dim ServerString As String = "Server=localhost;User Id=root;Password=password;Database=db"

        Dim SQLConnection As MySqlConnection = New MySqlConnection

        SQLConnection.ConnectionString = ServerString

        SQLConnection.Open()
        Try
            If sql.ExecuteNonQuery() > 0 Then
                SQLConnection.Close()
                ExecuteNonQuery = True
            Else

                SQLConnection.Close()
                ExecuteNonQuery = False

            End If

        Catch ex As Exception
            MsgBox(ex.ToString)
            SQLConnection.Close()
            SQLConnection.Dispose()
            ExecuteNonQuery = False

        End Try
    End Function
End Class
mi compare lerrore nell ultima parte in quanto non trova executenonquery. Dove ho sbagliato?