Inner Join?

[bmahler]

hmmmm. LodeDbException?? do you mean oledbexception?

place your query section in a try catch loop and catch the exception to get a more specific error message
ie

Try
            cmd = New OleDbCommand(strSql, con)
            dr = cmd.ExecuteReader
            Dim QueryResult As New ArrayList
            While dr.Read
                Dim dummy As New Average
                dummy.Name = dr("name")
                If Not IsDBNull(dr("average")) Then
                    dummy.Average = dr("average")
                Else
                    dummy.Average = "0"
                End If
                QueryResult.Add(dummy)
            End While
            dgvAverage.DataSource = QueryResult
        Catch ex as OleDBException
            MessageBox.Show(ex.Message)
        End Try