Private Sub TextBoxComN_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBoxComN.TextChanged
        Dim count As Integer
        count = TextBoxComN.Text.Length
         Dim ds As New DataSet
        If count >= 3 Then
            Dim command As String = "select * from persona as p, telefono as t where p.idPersona=idTelefono and ComuneN like" & _
            "'%" & TextBoxComN.Text.Trim & "%';"
            M.connessione.Open()
            M.adattatore = New MySqlDataAdapter(command, M.connessione)
            M.adattatore.Fill(ds, "Ricerca")
            DataGridView1.DataSource() = ds.Tables("Ricerca")
            DataGridView1.Columns(0).Visible = False
            DataGridView1.Columns(11).Visible = False
            M.connessione.Close()
        Else
            'svuota DataGrid
            DataGridView1.DataSource = Nothing
        End If
    End Sub

...
    
  Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DateTimePicker1.ValueChanged
        Dim ds As New DataSet
        Dim DateTime As Date = DateTimePicker1.Value.ToShortDateString
        Dim dataD As String = DateTime.ToString("dd")
        Dim dataM As String = DateTime.ToString("MM")
        Dim dataY As String = DateTime.ToString("yyyy")
        Dim dataForm As String = dataY & "-" & "-" & dataM & "-" & dataD

        Dim command As String = "select * from persona as p, telefono as t where p.idPersona=idTelefono and DataN =" & _
"'" & dataForm.Trim & "';"
        M.connessione.Open()
        M.adattatore = New MySqlDataAdapter(command, M.connessione)
        M.adattatore.Fill(ds, "Ricerca")
        DataGridView1.DataSource() = ds.Tables("Ricerca")
        'Console.WriteLine(DataGridView1.Columns.Count)
        'DataGridView1.Columns(0).Visible = False
        'DataGridView1.Columns(11).Visible = False
        M.connessione.Close()
  End Sub