Sub updateDataView()

        Select Case currentSet
            Case "items"
                cmd = New SqlCeCommand("SELECT items.id,items.name,items.price,categories.name from items inner join categories on items.category = categories.id", con)
            Case "clients"
                cmd = New SqlCeCommand("select id,name,phone,identificator from Clients", con)
            Case "receipts"
                cmd = New SqlCeCommand("select clients.name,receipt_id,date from receipts inner join clients on clients.id = receipts.client_id", con)
        End Select
        If con.State = ConnectionState.Closed Then con.Open()
        myDA = New SqlCeDataAdapter(cmd)
        myDataSet = New DataSet()
        If myDataSet.Tables.Count > 0 Then
            myDA.Fill(myDataSet, currentSet)
            MainGridView.DataSource = myDataSet.Tables(currentSet).DefaultView
        End If

        con.Close()
        MainGridView.Focus()
    End Sub