Returning mysqli results outside of function - php

Question

Given the following code:
function fetchData($mysqli){
$sql = "select * from `test`";
$result = mysqli_query($mysqli,$sql);
return $result;
}
$result = fetchData($mysqli);
while($row = mysqli_fetch_array($result)){
echo $row['id'];
}
My code is obviously more complicated than this. It loops itself until it yields some results changing some variables at each iteration.
$result is empty. What am I doing wrong? Thank you!
FULL CODE:
function fetchItem($itemID, $period, $mysqli){
$periodArray = array('7', '30', '60', '90', '180');
while (current($periodArray) !== $period) next($periodArray);
$currentPeriod = current($periodArray);
$sql = "SELECT * from `test` where `period` = '$period'";
$result = mysqli_query($mysqli,$sql);
$row_count = $result->num_rows;
if($row_count < 5){
$currentPeriod = next($periodArray);
fetchItem($itemID, $currentPeriod, $mysqli);
} else if($row_count >= 5){
$currentPeriod = current($periodArray);
$rows = array();
while ($row = $result->fetch_assoc()) {
$rows[] = $row;
}
// var_dump($rows); <-- returns all results
return $rows;
}
}
$output = fetchItem($itemID, $period, $mysqli);
echo '<pre>';
print_r($output); <-- NULL
echo '</pre>';
As you can see if I don't get results for a given period it moves onto the next one.

Answer 1

Your code should be:
function fetchData($mysqli){
$sql = "select * from `test`";
$init = mysqli_query($mysqli, $sql);
$result = $init->fetch_array(MYSQLI_ASSOC);
return $result;
}
$result = fetchData($mysqli);
foreach($result as $row){
echo $row['id'];
}