csv_from_result: You must submit a valid result object

[eluser]EEssam[/eluser]
Hi,

I'm getting the following error message:

You must submit a valid result object

Why trying to do:

Code:

$this->load->dbutil();

        $query = $this->db->query('SELECT * FROM user');

        $data = $this->dbutil->csv_from_result($query);

I tried the following and the rows are being correctly printed to screen:

Code:

foreach ($query->result() as $row)
{
    echo $row->userid;
    echo $row->username;
    echo $row->email;
}

So I don't see how I must submit a valid result object

Please let me know what's wrong. Thanks.