Fatal error: Call to undefined method CI

Hi guys, I'm having this problem when trying to generate an excel file with the data that is displayed on the screen. Clicking will show this error.

Fatal error: Call to undefined method CI_DB_mysql_utility::csv_from_array() in C:\wamp64\www\application\controllers\fluxo_caixa.php on line 259

help? 

Try this 

Code:

$query_str="whatever your sql query maybe";
$query=$this->db->query($query_str);
$result_array = $query->result_array();
$fp = fopen('file.csv', 'w');

foreach ($result_array as $rs) {
   fputcsv($fp, $rs);
}

fclose($fp);

The snippet will get your result array and write to csv file.  Just make sure you set correct permission on 'file.csv'.  Also on query_str
if you need to pass on param within the sql statement then you need to use $this->db->escape($param), e.t.c

You can use active record method as per doc it will auto escape the param for you , how you want to write it is up to you

Regards