Private Ds As DataSet
    Private ConnString As String = "TuaStringa di connessione"
    Private Conn As SqlClient.SqlConnection
    Private Da As SqlClient.SqlDataAdapter
    Private Cmd As SqlClient.SqlCommand

    Private Sub PopolaDataset()
        Conn = New SqlClient.SqlConnection(ConnString)
        Cmd = New SqlClient.SqlCommand("SELECT IDAna, Dal, Operativa FROM Operativa WHERE IDAna = @IDAna order by Dal", Conn)
        Cmd.Parameters.Add(New SqlClient.SqlParameter With {.ParameterName = "@IDAna", .SqlDbType = SqlDbType.Int, .Value = Combobox1.selectedvalue})
        Da = New SqlClient.SqlDataAdapter(Cmd)
        Ds = New DataSet
        Da.Fill(Ds, "Tabella1")
   End Sub