Defining and calling custom function - php

Question

I have a block of code that works perfect:
$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select(array($db->quoteName('date')));
$query->from($db->quoteName('#__webfoot_minutes_and_agendas'));
$query->order('date DESC');
$db->setQuery($query);
$results = $db->loadObjectList();
Until I try to assign it to a function:
function call_db() {
$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select(array($db->quoteName('date')));
$query->from($db->quoteName('#__webfoot_minutes_and_agendas'));
$query->order('date DESC');
$db->setQuery($query);
$results = $db->loadObjectList();
return $results;
}
It breaks when I try to call the function, I get an error for $results I get, "Invalid argument supplied for foreach()...:
call_db();
foreach ($results as $result) {
$dateArr = explode('-', $result->date);
if (!in_array($dateArr[0], $already_echoed)) {
echo '<li>' . $dateArr[0] . '</li>';
$count++;
}
$already_echoed[] = $dateArr[0];
}
Anyone have any suggestions on how I can straighten out this syntax?

Answer 1

You have to assign result of your function to variable.
$results = call_db();

Answer 2

Though it is awful design:
foreach (call_db() as $result) { ... }

Answer 3

You haven't assigned return value of call_db() to anything. You have to assign it first to $results
$results = call_db();
And, after that it is better if you check that the $results is an array. See this.