php data_seek in user function - php

Question

I have connection with mysql & need to get query results many times.
I use:
$mysqli = new mysqli(DB_SERVER, DB_USER, DB_PASS, DB_NAME);
Then query:
$query = "CALL raport6('2014-01-01', '2014-12-31', 300);";
$result = $mysqli->query($query);
I have function in separate file which gives me header names:
function headers($result) {
global $result;
$field_cnt = $result->field_count;
$string ="";
while ($finfo = $result->fetch_field()) {
$currentfield = $result->current_field;
$string .= "'" . $finfo->name . "'";
if ($currentfield == $field_cnt) {break;}
$string .= ",";
}
$result->data_seek(0);
return $string;
}
Then I call this function twice, and get only 1 (first) result:
echo "function 1:" . headers($result);
echo "function 2:" . headers($result);
I used $result->data_seek(0); to reset pointer... but it doesn't work in function. If I use function code in file twice - then it works.
Do you know why?
Cheers!

Answer 1

You could make that function a whole lot simpler
function headers($result) {
$string = '';
while ($finfo = $result->fetch_field()) {
$string .= sprintf("'%s',", $finfo->name);
}
// and here is the fix
$result->field_seek(0);
// to remove last comma if required
// return rtrim($string, ',');
return $string;
}