$DB = new PDO($dsn);

//Why does this work
$sql = "SELECT column FROM table WHERE id = 5";
$true = $DB->query($sql);
if($true) {
    $results = $true->fetch(PDO::FETCH_ASSOC);
    print_r($results); // shows results
}

// But this doesn't work...
$sql = "SELECT column FROM table WHERE id = ?";
$ids[] = 5;
$statement = self::$DB->prepare($sql);
$true = $statement->execute($ids);
if($true) {
    $results = $statement->fetch(PDO::FETCH_ASSOC);
    print_r($results); // shows empty
}

// :(